2023, and we focused in that period of time that it was suspended on debt reduction, obviously. As a result, we ended 2024 with net debt of $28 million, equating to less than one time's leverage. We indicate here that we had $2 million of share repurchases last year, even though we didn't have an official share buyback program. That represents net settlement for employee grant vesting. DHI is effectively a holding company for two different brands. They're two tech-oriented recruiting platforms named Dice and ClearanceJobs. We create platforms that allow our clients, who are recruiting recruiters as well as hiring managers, to connect with technology candidates, technology professionals in the United States. These are two-sided marketplaces that serve both the needs of the clients as well as the candidates themselves. You might say that that sounds pretty familiar with the likes of Indeed and ZipRecruiter.
They do a lot of advertisement constantly on TV or in radio. We are different in that we are a specialist platform or two platforms that focus exclusively on technology professionals. As a result, we have built specialized search algorithms to find candidates based on their actual tech skills. Secondly, we have spent literally decades, 34 years in the case of Dice, 22 years in the case of ClearanceJobs, bringing the highest quality talent to these platforms. Today, we have over 8 million technology profiles in both of these platforms across both of the two platforms. That represents about two-thirds of the total skilled technologists in the United States. The benefit of being around for almost a third of a century. We make money by charging our clients for subscription contracts that allow them to access the platform.
It is a charge to the recruiter or the hiring manager, and it's free to the candidate for right now. Over 90% of our revenue is recurring as a result. The United States has become more of a technology-oriented economy over the course of time, and we have grown the tech workforce traditionally over the last 30 years by about 3% each year. There have been aberrations for the Great Recession, for the dot-com implosion, for COVID, but for the most part, the tech workforce grows at the same rate approximately as GDP. We have a unique set of candidates that cannot be found on other career sites. Based on our research, roughly 20-30% of our candidates can be found on alternative sites like CareerBuilder plus Monster, ZipRecruiter, Indeed, or LinkedIn.
If they are found there, they generally do not have an updated profile, or they do not have a resume and contact information. We are very unique. ClearanceJobs is the dominant leader in its market for delivering access to technology professionals with a government clearance. ClearanceJobs really does not have a competitor today because LinkedIn does not have a field for clearance. There were restrictions that were put in place several administrations ago telling federal workers as well as military contractors that have a government clearance not to use LinkedIn because it is a target for foreign spies. Tech professionals are very well compensated. The average salary for a tech professional as of last year was $111,000. The average worker in the United States makes approximately $50,000. That's a salary figure for both.
As a company interested in finding a tech professional, you fundamentally have two different choices when you're trying to find one. You either use a recruiter or you do it yourself. If you use a recruiter, you'll generally be charged between 20% and 30% of the first year's salary for that worker, that tech professional. The alternative is to pay for a license to either Dice or ClearanceJobs, and that's roughly $8,000-$10,000 per year for a subscription, or at least our simplest entry-level subscription to those platforms. You would essentially try to engage the talent yourself and make that hire for a much lower price point than you would pay for a recruiter. It is important to understand that we've been around for a long time.
Nevertheless, as you can see from this particular article that came out in Forbes middle of 2024, they rated us the top job board for tech and IT jobs. The bottom line is that the elevated interest rate environment that has been imposed by the Federal Reserve has clearly depressed hiring demand. It was intended to do so. That is true of the tech sector, less so than other sectors, but still has been depressed over the last couple of years. As we believe, just about every single business in the United States has some form of technology component to it, or it is evolving to incorporate technology. There is a long-term trend towards more technology professionals in the United States.
This particular graphic comes from the Bureau of Labor Statistics as well as CompTIA, which is an association of tech professionals in the United States that indicates that the tech workforce will grow by at least 18% over the period of time 2024- 2034. That is twice as fast as the overall employment growth rate. There are two dominant occupational trends in the United States that have been persistent for many years. There has always been more and more healthcare workers, and there has always been more and more technology workers.
If you looked at the very small font on the right-hand side of this chart, you'd see that the growth is coming from interest in skills that you would logically suspect, the need for ever more data scientists and engineers to implement AI, more cybersecurity engineers to protect us from ever-increasing threats, and armies of software developers to create more code to make our businesses more automated in general. I want to explain a little bit more about the necessity of focusing on skills in both of our platforms. It's the reason why our two platforms are very unique. LinkedIn and other career sites create a user profile based on titles. The concept of skills are soft skills like public speaking. Our special sauce comes from the fact that we have this taxonomy of over 100,000 tech skills that we manage.
Our profiles, as well as the job search algorithm itself, is based on finding people with the exact skills that you need for your tech stack or tech environment. We win in this market for tech talent because we are specialists in technology skills and not a generalist recruiting platform. Here are a couple of case studies that we want to illustrate the great relationship we have with our customers. In the first case, Leidos has been a client of ClearanceJobs for over 10 years and has continuously increased its spend with us. The second case study is Montefiore Healthcare System out of New York City. They have been a client of Dice for over 10 years and have more than doubled their spend with us over the course of time. Montefiore's case study also illustrates something that a lot of people don't understand about Dice.
We do have the FANG companies as our customers, but we would say that our best value proposition is really for those customers that are not that easily distinguished inside of the economy of the United States because they're not as visible to the tech community. Every technology professional knows how to find the career page for Amazon, for Google, for Facebook, but not so much for Home Depot or Disney, who are current customers of ours. The opportunity for ClearanceJobs and Dice is associated with the TAMS that we illustrate here. We have, in the case of ClearanceJobs, approximately 1,900 subscribers today. The government has publicly stated that there are over 10,000 contractors that hold a facility clearance, allowing them to conduct business with cleared personnel. We also know that there are over 100 federal government agencies that can directly contract with us as well.
In the case of Dice, we have approximately 5,000 subscription clients today, and we know that tens of thousands more fit our ideal customer profile. There are also thousands of additional staffing recruiting firms that can target us as well. Before I transition to Greg, I want to leave you with this quick summary of how do we make money and how we have strong visibility into the future revenue profile of the company. First and foremost, clients pay for the opportunity to access the platform, as I explained earlier. There is no charge for a candidate to register, create a profile, or start using the platform today. As I indicated earlier, because we have our subscription-based service with a one-year minimum term, over 90% of our revenue is recurring.
Over 90% of our contracts actually include an auto-renewal provision that has a price escalator built into it. The nature of the subscription is that we cap the number of profile views each contract has based on the number of recruiters associated with the institution, as well as their intended number of tech professionals that they plan to hire for the following year. If you think about it, Robert Half, which is one of our larger customers, has a completely different number of profile views than a 100-person tech firm. That's another key differentiator that makes our platform more effective than those of LinkedIn, Indeed, and CareerBuilder. We focus on these profile views, but we encourage unlimited communication in the form of our own private email service on the platforms, as well as our own messaging service.
We want the recruiters and candidates to engage as much as possible so that they can essentially have a better relationship and ultimately culminate in a hiring decision by the firm. With that, I'd like to introduce Greg Skippers, our CFO, to take you through the rest of the presentation. Greg?
All right. Thank you, Art. I'm going to try to get through some of the numbers here fairly quickly for you so that you have plenty of time for Q&A at the end. Of course, if we want to go through anything at a later time, more than happy to do that. DHI bookings, which represent the value of our contracts that will be recognized as revenue within 12 months of the start date, have risen at a 6% CAGR since 2020, and revenue has also risen at the same 6% CAGR over the same period.
With over 90% of our bookings and revenue recurring, DHI is a very predictable revenue model with approximately 50% of each year's revenue already under contract at the start of each year. Our adjusted EBITDA margin has expanded since 2019 to 25% in 2024. Because of the more difficult market conditions in 2023 and 2024, we reduced costs through restructurings in the second quarter of 2023, in the third quarter of 2024, and again earlier this year. Together, these restructurings have reduced our operating costs by approximately $20 million. The restructure earlier this year also separated our Dice and ClearanceJobs organizations, which is designed to better deliver results for our shareholders, maximize profitability, and provide stronger long-term strategic options. We continue to target a 24% adjusted EBITDA margin for 2025.
As previously mentioned, challenging market conditions in the HR tech space have persisted in 2024, with bookings and revenue declining in the mid to upper single-digit range. We have, however, managed our cost structure to grow our adjusted EBITDA margin to 25% in 2024. Our subscription-based business creates predictable revenue, with revenue generally being recognized ratably over the annual contract term as services are delivered to our customers. This slide depicts how our committed contracts at the start of 2024, shown as backlog, become revenue over the year, and then how our customers up for renewal during the year drive revenues as the year progresses. The remainder of our revenue comes from our new business efforts and our transactional business, which primarily includes short-term job postings, career events, and our sourcing services product.
DHI produces strong operating cash flows with the low points for operating cash flows over the past five years approximating $20 million, and the strong markets in 2021 and 2022 driving operating cash flows to $29 million and $36 million, respectively. DHI's capitalized development costs, which are part of fixed asset purchases in our cash flow statement, primarily represent the cost of our internal labor to build the products and features on the Dice and ClearanceJobs sites. With lower internal headcount resulting from the restructurings, capitalized development costs are expected to continue to decline into 2025. By consolidating our tech organization to a smaller number of teams that have subject matter expertise in adjacent areas, we have found that we can accelerate our release schedule. DHI's free cash flow, which is operating cash flows less capital expenditures, is driven by adjusted EBITDA levels and our capitalized development costs.
Over time, we're targeting free cash flow at approximately 10% of revenue. As Art mentioned, we suspended our share repurchase program in the middle of 2023 to focus on paying down debt. Our debt at the end of 2024 was $32 million, resulting in a leverage of 0.91 times our adjusted EBITDA levels. We generally maintain approximately $2 million of cash on hand and utilize our $100 million revolver to manage liquidity. Since 2019, DHI has repurchased nearly 18 million shares and has reduced shareholder dilution by approximately 6 million shares, or 11%. Earlier this year, we announced a new buyback program, which allows us to repurchase up to $5 million of common stock through February of 2026. Our ClearanceJobs brand is a dual-sided marketplace with 2024 revenue of $54 million, comprised of approximately 2,000 clients. The overall market has over 10,000 cleared employers and over 100 government agencies.
These logos represent a sampling of our ClearanceJobs customer base. ClearanceJobs quarterly bookings have seasonality, with the first quarter being the largest of the year. ClearanceJobs bookings have a five-year CAGR of 15%, and most recently, Q4 bookings were flat year over year as the defense budget continuing resolution and uncertainty due to a possible government shutdown, as well as the change of administration impeded CJ bookings in the fourth quarter. Even with these headwinds, ClearanceJobs' renewal rate for the fourth quarter was 93%, and its retention rate was 111%. ClearanceJobs' revenue has a five-year CAGR of 16%, with the fourth quarter of 2024 being up 7% year over year.
Dice is also a dual-sided marketplace that drove $88 million of revenue in 2024 and is comprised of approximately 5,000 subscription clients and a market with roughly 100,000 client opportunities between the commercial and staffing, recruiting, and consulting accounts. This slide shows a handful of notable Dice logos. Our market opportunity in commercial is comprised of companies across various industries, such as Coca-Cola, Disney, and Bank of America, who aren't traditionally tech companies but certainly hire many tech professionals every year and leverage our platform with their tech hiring needs. Now on to Dice bookings. Dice's quarterly bookings also have seasonality, with the first quarter being the largest of the year. Dice bookings have a five-year CAGR of 2%, and most recently, Q4 bookings decreased 14% year over year as the HR tech hiring environment has remained challenged.
Dice's renewal rate for the fourth quarter was 77%, while its retention rate was 97%, demonstrating the continuing need of Dice's services by its core customers. Dice revenue has a five-year CAGR of 2%, with the most recent quarter being down 14% year over year, similar to bookings. McKinsey and other economists predict tech hiring to grow in double digits over the next 10 years, and DHI is at the intersection of fueling the tech economy. Our pool of millions of candidate profiles, coupled with our platform-enabled proprietary matching algorithms, allows for efficient and effective identification of talent and ultimate hiring. In summary, DHI is well prepared to capture growth in tech hiring in the coming years. With that, we're happy to take any questions you may have.
Questions? Five minutes, I believe, for Q&A. Welcome any and all questions. Yes, sir. It does definitely affect the Dice business.
The Dice business, again, is one that is really correlated very closely to the state of the economy. We would say it's incredibly correlated. Like we've done regression analysis that show that the regression coefficient is like 90% of the number of new tech job postings that appear every single month. We're at about 70% of what we consider to be normal number of tech job postings. We're still climbing back to what we consider to be like a normal year of 2019. ClearanceJobs, on the other hand, are really correlated to the defense budget because we're facilitating military contractors hiring tech professionals. Last year was a challenging year because there was a lot of dissonance in the government. We were constantly worried about going into a government shutdown. We were negotiating over the debt ceiling being increased.
We were under continuing resolution, which is not a real budget for most of the year. We do believe that this year is going to be a much better year for ClearanceJobs because we have a single-party government. There is belief that we will get to a $1 trillion defense budget, which will be a substantial increase based on what we've seen in the past. Most defense budgets over the last 20 to 30 years have gone up by about 3%. That is a 12% increase if it does get to a $1 trillion mark. The brands definitely are affected differently. The other interesting thing about ClearanceJobs is that military contractors are about 63% of EU defense procurement spend. If the EU does increase their spend, they are going to have to go to military contractors in the United States to actually make it effective. Great question. Yes, sir.
That's a great question. There are two dimensions to that. I'd say that in years past, we have increased CJ pricing, ClearanceJobs pricing, by approximately 5% each year. It does have a competitive benefit of not really having anybody that we have to worry about. Like I said earlier, LinkedIn is not a competitor to ClearanceJobs because there is no field for clearance inside of a profile. The other aspect of pricing is that about a year ago, we decided to bundle a whole bunch of different components that we felt were leading to success for our top firms into what we call a pricing bundle. We kind of changed the nature of pricing for both platforms in order to essentially get a lift as well. Sir, that's a great question.
I'll tell you that we used to have other verticals, and we sold a number of them back in 2018, 2019. I really believe that we have to follow occupational demographic trends. As I kind of alluded to, there are two trends that have been persistent over the last 20 to 30 years, and that is that as we get older over the course of time as a population, we're asking for more healthcare workers, and we have constantly increased the number of technology professionals. If there was a platform to buy, I would buy it in something that was or start it, it would be in healthcare, for sure. I think we're getting close to time. We're about five minutes, I think. We just want to say thank you very much.
If you're interested in having another discussion, we have our booth that's in the main hall and would welcome a meeting. Thank you. Absolutely. Thank you. Okay. I think
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