He's CEO of the company. I remember very well when Greg joined the company in early 2005. It was a tough environment. Prices in the property casualty side were only going down for the foreseeable future. Greg, on one of his first conference calls, expressed a lot of enthusiasm for the business. We kind of scratched our head and said, "What's so exciting? It's a very tough business." You can see over the past six years what Greg and his team have done at the company and the changes that have occurred there. Investors like to look forward and not backwards. We're lucky to have Greg here to talk about Aon and the future and what they're doing. Greg?
Thank you, Jay. I appreciate it. Just appreciate a chance to be part of the conference today. I'm going to provide a bit of overview of the firm and what we've been up to over the last few years and what we're thinking about over the coming years. I'll be joined in a moment by Scott Malchow, our Head of Investor Relations. Christa Davies would've been here today. She has a very severe sinus infection. About 20 doctors kind of battled her back from getting on the plane. She's also available to answer any questions if you've got comments or questions at any point. What I think I'm going to do with the time, I want to focus on three things. I understand that not everybody's that familiar with Aon, the first part of my message is going to be literally, this is Aon.
I want to tell you about our mission, our objectives, our firm, and where we are today. Literally, the overall description of what our firm is about and the assets we have in place today to serve our clients and to serve our partners and shareholders. Next piece of the conversation, it's important I talk to you a bit about how we've gotten here. As Jay described, really the journey over the last six years. By the way, we want to do that because we want to show you progression. We believe there's some meaningful messages in the history as a prologue to the future in terms of our ability and our conviction to actually get things done and move the firm forward. That's the second part of the discussion.
The third part of the discussion, as Jay described, is the most important. That's our plans for the next six years. As the firm moves forward, the operating capability we have in place today, the financial strength we have in place today to serve the marketplace, support clients, and support colleagues who are going to support clients. Let me start with the first part of this. Again, for those who aren't as familiar with Aon, we're a fairly simple firm. Aon is focused on two topics and two topics only, risk and people. Our focus is really helping companies around the world understand, measure, mitigate risk. All kinds, traditional, non-traditional, whatever type of risk a company's looking at, we're focused on it. The second part of the mission is around people, helping companies with their most important people issues.
Pensions, retirement, health and benefits, talent, and rewards. Literally, it's a fairly straightforward firm focused on risk and people, the mission against that. You should understand against that mission, the platform is quite formidable. We are the number one platform in the world looking at commercial risks, bigger than anyone in the world we've evolved over the last number of years. We touch more companies every day on the topic of risk globally than virtually any firm in the world. In reinsurance, the opportunity to serve Mr. Sharma and others as they think about their return on invested capital and strengthening their business. Our reinsurance business, also the number one platform in the world. More content, more capability, we believe, humbly, than anyone out there. I'll talk a little bit about that. Number one in captive management, a leader in affinity.
The risk part of the mission, the platform we have and the risk part of the mission is we believe the single strongest platform in the world at looking at risk today, as you think about a risk advisor. The second part of the mission on HR solutions, also a very strong platform. Number one in benefits administration, as we help clients think about this very important part of their business. Number one in business process outsourcing, and a leader in HR consulting. This is the mission of Aon around risk and people. About 60% in risk, about 40% in people. That's our focus, nothing else. The platform that underpins that mission is also quite formidable. When you think about our firm, I said we serve more companies every day on the topic of risk than virtually anyone in the world.
If you look at the left-hand side of the page, that's where we are. 120 countries, over 500 offices around the world. It's the single biggest fixed network helping clients address risk we believe that's out there today. Very formal. It's a very, very unique asset that's been built up over many, many, many years. Long before Greg Case arrived, this network was in place, an incredibly powerful network. On the right-hand side, you can see Aon's a very global firm. We are a firm serving risk and people. We do it everywhere around the world. In fact, over half of our business is now outside the U.S., as you think about the mix on the right-hand side of the page. Back to risk. I said we placed a lot of risk.
Over $100 billion of premium a year, when you think about what we do on the commercial side, what we do on the reinsurance side, what we do on the health and benefits side. Again, touching more companies every day on the topic of risk than virtually any firm on the planet. Very strong technology underpinning. We may not have gotten it all right, but I can tell you we've invested more in content capability and technology support for our clients than we believe anyone in the industry. It's a very, very important part of the value proposition, which I'll talk about in a little bit. On the HR solutions side, a world-class brand now in place. Tremendous capability that really cuts across the gamut of everything you think about when you think about pensions, retirement, health and benefit, talent rewards.
The platform risk and people, global platform underpinned by an exceptionally strong global network. If Aon is about risk and people, I'm here to tell you that we are very excited about this space. As Jay said, early on, I was excited about serving in this topic. I still am. By the way, I would say seven years ago, six and a half years ago, when I had the privilege of joining Aon, the topic of risk was an important topic. I would suggest it's more important now than ever before. In fact, when you think about what's going on in the world of risk, I kid you not, I literally was in Europe last week, in France and in Italy, you literally open the paper, risk is everywhere.
This little topic of risk that Aon's got this great platform to serve is now bigger and badder than ever before. There, in fact, are more risks today, we believe, than ever before. All the traditional stuff which are reflected here, as you look at the low to mid-single digit growth in premium, but also the non-traditional risk, the risk of sustainability, global warming, pandemic, cyber risk, terrorism, et cetera. More risks than ever before. By the way, more complicated than ever before. We all know our clients woke up and realized that a flood in Thailand was a tragedy, it was a catastrophe, but it was also a global supply chain problem. The integrated world of risk is getting bigger and badder, and that's what Aon does. We help clients understand, measure, and mitigate all those risks. We like that segment.
We believe that's going to get more and more significant over time. On HR solutions, think about everything that's happening. The world of healthcare is becoming more complex everywhere. Everywhere on the planet. By the way, it's very different by country, but it's always complex. By the way, always quite meaningful from the standpoint of how clients have to react and address a very important and growing cost on their P&L, and by the way, an important topic as they support their employees, and that's where Aon comes in. When you think about who we are, again, won't spend a lot of time on this area, but we are a firm focused on risk and people with an exceptionally strong global platform underpinning that, touching more companies every day on both of these topics than virtually anyone in the world. Very global.
Those two topics, by the way, we believe are increasing in demand and in complexity. That's a little bit of a picture of who Aon is. Happy to address any more questions in the Q&A on that. It's important you understand how we got here, and the reason Scott and I want to spend a little time on this is if anyone gets confused about our conviction around risk and people, you need only look at our history to understand what we've undertaken to get here. Go back to 2004. Our firm was 55% risk, 13% HR solutions, and about a third, 32% of our firm was, in fact, underwriting. We did what Mr. Sharma did, not in the same category, not as well, not even close. We had a balance sheet, and we literally were an underwriter. A third of Aon was underwriting.
At that point in time, we stepped back, we made a set of decisions that literally have shaped our history. The decisions basically said, look, the place where we can truly be world-class, the place we can make a difference that's sustainable, that can make a difference for our clients and make a big difference for our shareholders, are on these two topics of risk and people. We undertook a series of steps that have completely, as you can see here, reshaped our portfolio. We sold Combined Insurance, we sold warranty, we sold construction underwriting, we sold AIS, we sold premium finance. In the end, we sold all of the underwriting businesses, all the capital-intensive balance sheet businesses, Aon got out of.
You look at the right-hand side of the chart, you see where we are today, about 60/40 risk and people, balance sheet light, truly a firm of 60,000 colleagues around the world helping clients every day on these two topics. That's the firm out of all the balance sheet businesses. Again, if you're confused about our level of conviction around this, we changed a third of our firm to position ourselves to go attack this in an effective way. We believe that structural change has been a big part of setting the platform today for Aon. In addition, it's important, as Jay described at the beginning, listen, the last six years have not been the easiest. I caught the last part of John's discussion, and he was articulating it very well. If you think about the last six years, what's gone on?
We've had an insurance market that's got a tremendous amount of pressure, prices going down 10%-15% real every year. We have interest rates which are as close to zero as one can imagine. We throw in a global economic recession, right? How much more bad can the mix get? That's, in fact, been the last five years. Understand Aon in the context of that over the last five years structurally changed the portfolio to focus on risk and people, and, now this is an important and, we made a series of investments. We have to. We have a great passion to build our firm for the long term and to deliver annual performance. Both. We realized we couldn't just maximize short-term return. We needed to invest to build the firm for the long term. Here are nine examples. There are many more.
How we think about the year in the life of an Aon client, Aon Client Promise. How we think about amassing, when you think about $100 billion of premium moved every year, that's more than anyone in the world. To be able to pull that together and understand it in something we call the Global Risk Insight Platform, which is now the single large repository of insurance information we're aware of in the world today to help our colleagues serve clients, is a big investment for us. By the way, it took a number of years before we started to see the return on that. We're just now starting to see that. What we've done in systems, we call it Revenue Engine. We had 37 selling systems at one point in time, which by the way, is okay, just how the firm evolved. We couldn't do 37 selling systems.
We need to boil that down. We made significant investments over the last six years to build our firm. Here are some of those examples. We also needed to perform. Think about the complexity. In a world in which we're structurally changing our portfolio to risk and people, we're making substantial investments in building the firm. We also, over that period of time, were able to grow basically five out of six years. By the way, the year we didn't grow over that period of time, we shrank by 1%. We've been able to largely grow our firm. From a performance improvement standpoint, overall operating margin, and I'll break it down in a bit between risk and HR solutions, we've increased 490 basis points over that period of time. EPS has grown at 19% per year over that period of time.
While we're not satisfied with this performance, we feel good about this performance in the context of the investments we've made for the future of our firm. The history and sort of what was going on in the overall context, and for the structural change we've made to position Aon. Again, stepping back, this is a firm focused on risk and people, that over the last six years has made substantial investments and produced this set of performance. This performance, in concert with the investments, we believe is an important combination. That's what sets the stage for the most important part of this discussion, which is how we think about what's coming next. The next six years. I want to talk about two things. One is sort of the operational foundation that's in place now at Aon. It will continue to evolve.
I don't want to, for a minute, suggest that we're complete here. We're going to keep investing in our business. The operational underpinning of where we are at Aon right now, we believe is unique. When you think about what we have in place that now we believe will start to kick in and help us grow our business. Everything from literally how we think about serving clients, which is salesforce.com and the Revenue Engine, to a set of risk analytics in terms of how we think about amassing what is a very formidable set of capabilities. For example, in Aon Benfield, 1,700 colleagues, 500 of which are Ph.D. statisticians, do catastrophe modeling, impact forecasting. Literally, these are the folks who develop flood models and quake models and all the different things you would see around the world.
If the wind blows or the earth shakes, they can tell you literally what the impact is on our clients at a sub-ZIP code level. That set of analytics is powerful. That's part of what we believe will help us grow in the future. Additional market analytics I described around the Global Risk Insight Platform, very unique in terms of our ability to understand what's going on in the world of risk. I mean, quite literally, typically, when you ask a risk advisor or a broker like us, if you're a client, "Did you get a good deal?" The brokers are going to say, "Of course. I'm a great broker. I know the market.
I got a good deal." Our brokers say that too, by the way, they're doggone good, they could also go to the Global Risk Insight Platform and say, "I know exactly what policies are being placed in your SIC code at your terms and conditions and limits around the world." The level of benchmarking just changed. Fundamentally just changed in a way that's hard to duplicate for anybody else out there. Client Promise, how we serve clients. Client Promise is something we're just beginning to put in place. Client Promise sounds simple. Literally, it's how we engage clients to listen, understand their needs, and drive performance. As we've looked at this, the retention rates on clients in which we go through Client Promise are five or six points higher than when we don't do Client Promise.
In markets where we don't do Client Promise, literally, when we lose clients, we often haven't done this. We know we have a set of proven tools and analytics in place that will help us build our business. This is one of those examples. This whole idea of Aon United. Quite simply, I've described a firm to you, focused on risk and people, that's a very global firm. Our clients do not benefit from that if we don't connect our global firm. If we operate as a whole series of regional firms or local firms, that's in fact what we are, regional and local firms with some overhead, that's even worse. The power of our firm comes to pass when we connect global Aon. Global capability delivered locally.
When our colleagues in London or our colleagues in Chicago or our colleagues in Zurich literally are sitting across the table from a client and can reach around the world and understand what's happening in terms of risk coverage, what's happening in terms of pricing, terms and conditions, and deliver that on behalf of a client, that's powerful. That's Aon United. That's something we're working on. It really is this group of investments on top of the current strength of Aon, which we believe puts us in a pretty unique position as we think about building the firm going forward. This would not have been possible without substantial investments over the last five or six years. You can't wake up and say, "I want to have this," and instantly get it. You have to truly invest behind it to do it, that's what we've tried to do.
In addition to the market-facing strength that we believe we're working on, long way to go, we're working on, we are also continuing to focus on operational excellence. We think about our strategy in terms of client, distinctive client value, delivering distinctive client value, creating a place for the best talent in the world, and operational excellence. We believe we have a record of work in this area that shows we accomplish what we say we're going to accomplish. Here are two examples. Aon Benfield, we show the restructuring program in Aon Benfield, the commitment around $144 million. We're fully on track to achieve that. In Aon Hewitt, the commitment to $355 million of synergies and fully on track to achieve that as well.
There's still benefit, particularly on the Aon Hewitt side, but even on the Aon Benfield side, still benefit for shareholders as we think about how we build the business. If you think about the next six years, that's a little bit of flavor from an operational standpoint of what we have in place in order to move forward and win in the marketplace and do so in a way that still builds margin. Both pieces critical from our standpoint, which gets us to our targets and where we're going to be. What we highlight for you here is, if you think about our risk solutions operating margin target, it's 26%, and our HR solutions margin target, which is 22%. If you go back in history and look at what we've done on the risk solutions side, I said I'd break this out for you.
This is the breakout risk solutions and HR solutions. It's increased about 500 basis points since 2006. We can talk more about that, how that breaks down, how that looks, et cetera. There are a whole variety of reasons as we think about sort of where it tailed off in 2011. It's basically flat up a bit if you take out a few non-recurring items, which you could talk about. We haven't taken them out here. We've thrown everything in. That's what we've done, increased 500 basis points. At the same time, we've made the investments that I've just talked about. By the way, in some respects, if you think about risk, what we've got is we had a period of time from 2006 to 2010. We knew the market was going to be difficult. We did not expect there would be a turn.
We certainly were not banking on a turn to drive Aon strategy. That was going to be driven by our team. We could not bet on the market to do that. In the context of that, with the restructuring program, we dropped money and created margin improvement and enough cushion to make the investments that we described. As the restructuring starts to roll off, which it's beginning to do, a few more years, beginning to do on the risk side, the investments we've made then fuel the next wave. That's what we're looking at to get to 26%. In many respects, we've described five specific steps or actions that are going to get us to the 26%. Three in our control around the Revenue Engine, around Aon broking, and around what we're doing around the Revenue Engine, and three outside of our control.
God forbid, insurance rates change or interest rates got above zero. Those two things would just accelerate it. They are not requirements to get to the 26%. Again, we're not expecting anyone to take us there. We are going to take us there. The first three steps, we believe, get us to a 26% over time. Same on the HR solutions side, 22% margin target. If you think about what we did, go to 2011. 2011, we were able to improve margin by 260 basis points in the first full year we've integrated Aon and Hewitt. While we want to do better and will do better over time, we felt like this is a pretty good step as we brought the two firms together. That's what we're trying to accomplish. By the way, the march to 22% we believe is also clear.
Capture the synergies, make sure we're getting a return of the investments out of the core business, and make sure the BPO improvements happen as we expect them to happen. It's not more complicated than that. That gets us to 22%. If you think about where we're going forward, what we're going to accomplish to get to the 26% and the 22%, we believe we've got the operating assets in place to do that, built up over many years, not last week or not last month or not last quarter. We've got a set of actions in place on the operating side for the restructurings, which will boost this. We have this set of investments which we believe will carry us to these two margin targets on the Risk Solutions side and the HR solutions side. That's the operating piece of this story.
Again, it's not that complex. Risk and people, very strong, unique platform globally, touching more companies every day on the topic of risk and people, a reasonable track record of performance improvement, a set of investments which we think will drive us forward and continue on that march of performance improvement. That's the operating story. Another piece of Aon. By the way, I get excited about the operating story. I get excited about what we can do for clients every day, the impact we can have. That matters a lot, by the way. If we don't do that fuels everything else at Aon. It's important as our potential partner investors, you understand the cash part of Aon. Aon was designed six years ago when we made a decision around risk and people. Believe me, we made a decision that had strategic merit.
We know these are areas we can compete in a sustained way and win. By the way, it also had financial merit. As we looked at return on invested capital, we cheated a little bit. We basically said we're going to drive operating performance, the numerator, and we're going to take capital out of the business, the denominator. The capital we took out was the underwriting capital. Very capital intensive, out. That means the cash generating capability of Aon is, we think, strong. Here's an example. If you literally look at what happened between 2010 and 2011, as Aon Hewitt comes online, operating cash flow increased 30%. Free cash flow increased 29%. By the way, the 29%, literally going from $603 to $777, has embedded in it a $300 million receivable on our balance sheet in an order to cash system we put in place in Aon Hewitt.
By the way, that's going to free up in the first quarter, second quarter. Put that $300 million on top of the $777, and literally the operating free cash flow went from $603 to over $1 billion. That's over a 70%-80% improvement in free cash flow from 2010 to 2011. The cash generating engine of Aon from a financial standpoint, with your hats on, we believe may be one of the most compelling parts of our overall story. Obviously fueled by the operating parts, but make no mistake about it, the cash generating engine of this firm is very powerful and getting stronger. By the way, we could stop there. The next part of the story we think amplifies the cash generating capability.
It's not only are we generating the cash, I just showed you that, going from six and change to over $1 billion on an operating basis over time. Our uses of cash, our need for cash. If Christa were here, she'd take you through the five or six uses of cash. We talk about pensions, we talk about restructuring, we talk about dividends, et cetera. We talk about buyback, which by the way, if you observe there, $828 million in 2011 is our most significant investment.
What's powerful about our cash story is not only is it strong, and by the way, not only will the operations make it stronger, if you took the operations and put them aside for a moment and said there was going to be no improvement, which will not be the case, the need for cash on the pension side, we now have a line of sight based on great work by Christa and her team to see how that's going to move down over time. If you think about that investment in 2011 and 2012, both on the pension contribution and the pension expense side, that's coming down. By the way, the restructuring investment's coming down. All of a sudden, the cash generating capability of our firm, even ex operations, is substantially increasing, which we believe is pretty unique in the context of what's going on.
The cash story of our firm, underpinned obviously by the operating story of our firm, we believe is fairly powerful. Finally, the other thing that will amplify this is our announced move as a Delaware company incorporation to London. What that will do with this cash picture is give us greater flexibility to invest around the world. We have said publicly, it gives us greater access to cash. We've highlighted $300 million that we get instant access to, but it really is, if you think about this picture, access to capability and cash over time, and an improvement in overall tax rate, which also will benefit us too, and again, gives us more to invest back into our business. Our story here, as I finish up, again, it's not that complicated.
We are a firm that has worked as diligently as we can, I can assure you, to focus on these two topics of risk and people. We are doing it in a time in the global economy. We think our clients need it more than ever. We think we've got a very strong platform, and it's getting stronger. By the way, we have a record over the last six years of improving performance, and we've invested to improve performance going forward. All that coupled with the cash-generating capability of our firm, which is strong and improving, again, up the better part of 80%, 2010 to 2011. Now uses of cash in areas that take away from free cash flow are going down.
In addition to that, we've announced the move to London, which gives us greater flexibility to use that cash, and also, by the way, a decreased tax rate over time, that we can invest back into the business. That's the story of Aon. We would love to take your questions or comments, and look forward to being supportive in any way we can. Please, go ahead.
Actually, let's go here first, and then we'll go over there.
Hi, just two questions. Number one, what do you think about the classic market hardening in 2012? Question number 2, can you tell me a little more about your new benchmarking system that you mentioned before? Why do you think it will be difficult for your competitors to reproduce that?
Sure. Actually, I'll use that GRIP. The question around the benchmarking system was the Global Risk Insight Platform. By the way, again, think about we move $1 billion of flow, but that literally overstates it for this purpose. Take out reinsurance, take out whole things like captives and a few other things, we've got about $40 billion or $50 billion of flow. Okay? By the way, we knew we had a lot, but we didn't really know exactly. Now we know exactly. We didn't track it. We literally didn't know what was happening around the world. Now we have 7,000 brokers who enter data every day. Okay? By the way, this is what it takes to duplicate GRIP. You need $40 billion or $50 billion of flow. That knocks out a lot of people. We have 7,000 brokers who enter the data every day.
That knocks out a lot of people. We have 100 colleagues in Ireland who are analytics folks who literally do fact-checking and data scrubbing to make sure it's not garbage in, garbage out. Literally, these are PhD statisticians literally looking at variance in the data, but also call center people calling people like me up and saying, "Hey, Greg, you put 1,000 in for this client last year. Now you're putting 10,000 in. Is it just a typo?" We have a tremendous amount of investment around scrubbing that data, and that's why we think the Risk Insight Platform is going to be slightly challenging to duplicate. Very few, in fact, could actually come close to that. The other thing that allows us to do is it helps us with clients, again, as I described before, benchmark quite uniquely, but also on this issue of price, commercial pricing.
We can do what everybody does and sort of get their surveys and have their gut feel and all. We can do all that. We do. We can also tell you that the Global Risk Insight Platform, when you look at Aon's entire system, literally was kind of -5% four or five quarters ago and has decreased five, four, three, two, now back to flat across our entire system. We will tell you the pricing of Aon is coming back to flat as of this quarter. By the way, trending up about a point a quarter, sometimes a point and a half, analytically, factually. By the way, our $40 billion is extrapolatable, we believe, statistically, to the market. We can tell you we are trending toward flat. By the way, in the context of that, huge variability. Obviously, cat exposed areas.
By the way, D&O was down, now coming back a little bit. We can tell you very analytically that we're sort of trending toward flat. There's still a bit of a supply-demand imbalance on the capital side, and if nothing happens over the course of the next-- over the summer, there will be, again, challenges, but rates have certainly trended toward negative with some positive spikes in different places around the world. That's your rate question and the GRIP question.
Okay.
I had two questions. One, given the sophisticated and extensive network that you describe with all the bells and whistles that you've been adding, do you think it's surprising that you haven't grown organically more than 1%-2%? I would assume you've got some strong competitive advantages in sort of how you talk about it. That's my first question. The second is, if I understand it right in the last call, you're increasing your investment in the BPO business from Hewitt, and my limited understanding is that was the most challenged part of their business when you took it on. I'm curious as to what you see, having been inside it now, that wants you to invest more into that area.
Great. Excellent. Two pieces. One, why haven't we grown more on the Aon Risk side, given the formidable capabilities? You're right. I ask that question a lot every day. I would say we feel very good about progress we're making on sort of number of clients we're winning. We're literally winning two-thirds. We literally track clients 50,000 and above RFPs when we win, when we lose, and we're winning two-thirds of those, and we feel like that's helped us tremendously. We've made some substantial investments in areas that we believe are going to be, in addition to what I showed you before in terms of kind of hard investments in content capability, we've made some big investments in sectors that we love long term. Believe me, they were not short-term helps. One of those examples is construction.
We've got a $250 million construction business in the U.S. and a $400 million-$500 million construction business globally. I can tell you, by the way, we are big believers in construction. We think the infrastructure rebuild of the globe which we now have full access to, is going to be formidable. For the last You counted two to three years, it's been a big pullback in terms of what we're up to. There are some mitigating factors that we think have literally kept us from growing as much as we think we will be able to over time. We feel, and a third of our book is fee-based. That puts a little bit of a damper in terms of what happens when rates move, et cetera. We feel good about our ability to grow that business going forward.
I think we're beginning to demonstrate that in the current marketplace. The opportunity for Aon, in low mid-single digits is formidable. Again, we improved margin at a time when rates were basically flat, and we were growing a little. We get a little more growth in the context of that, the opportunity for us from a performance improvement standpoint is actually quite substantial. Is that on that side? Okay. Happy to come back if you want to talk more about that. Aon Hewitt and our investments. We have made substantially new news on Aon Hewitt as we've made more investment than we would anticipated because we love a couple of spaces. It happens not to be the BPO space. By the way, the BPO space, for those who don't know, it's kind of very comprehensive service to a client.
It was the troubled area of Aon Hewitt or of Hewitt before we bought or brought that company in. Jim Konieczny has done a phenomenal job. It's about 30-35 contracts. That's progressing exactly as we hoped it would. It literally was negative trending toward mid-teens, and it's doing exactly as we hoped it would do. We might invest pieces, and we will invest in pieces of it for sure to continue to grow that. The bigger investments we've made are in new areas, like exchanges. In essence, as you think about what's happening in the healthcare space, we love this space. We think there's a huge amount of opportunity here. Think about on the healthcare space, you can take it against asset management, where you had defined benefit or on the pension side, where you had defined benefit moving to defined contribution.
That's starting to happen in the health space, where employers literally say, "I really would like to get rid of this liability if I can, but I don't want to give my employees to someone I can't trust." There's an opportunity to think about healthcare exchanges both on the retiree side and on the primary side, and we're investing in that. On the other piece we're focused on is in investment management, on the consulting side. Those are the places where we've seen significant opportunities to invest, and we have in fact done that. Again, that's not been accretive to short-term margin, as we know, but we have a model that we believe will help us really drive that business going forward, just as we've done on the risk side. Mm-hmm.
We squeeze one more question in if anyone has one.
Yes.
Talk about the very substantial cash flow that's going to come through. Maybe talk again about prioritizing how you plan to deploy the cash flow.
Yes. If Christa were here, she would literally take you through the five or six uses of cash, and she would take you through the return on invested capital approach we use. We literally allocate capital by return on invested capital. Highest return gets the capital. That's why share buyback is $800+ million, and it's been a very significant $4+ billion over the last few years, right? That's the piece. We have some absolute requirements obviously around pension contribution, which we showed before, restructuring, wind down, sort of current restructuring, eventually wind down, around dividends, all the things you would expect. We also will spend about, call it $2 million-$300 million a year. It'll vary. Last year was $130 million, $133 million on acquisitions. By the way, we don't see big structural acquisitions in our future. We've got those set.
We have the platform, but places where we can add content and capability, like Glenrand MIB and SIB in South Africa, are places where we can add content that really help us succeed. Those are the kinds of things we're thinking about. Share buyback is probably, if Christa were here, she'd say maybe number one and two or maybe three on the list. Okay, thanks very much.
Thanks.