Hello and welcome to Oxford Instruments' full year results. In the presentation, I will summarize the highlights for the year and hand over to Gavin for the financial results before returning to cover progress with our Horizon Strategy, Sustainability Agenda, our COVID response, an operational review, and closing with a summary and outlook. Moving straight to the highlights, I've been pleased with the performance of the group in the face of an extremely challenging environment. Our robust performance is testament to the resilience of our business model, positioning us in attractive and diversified end markets with a relentless drive to support our customers and improve our operational efficiencies, and was underpinned by the agility and commitment of our employees to embrace new ways of working.
The group delivered strong order growth, reflecting the underlying strength of our end markets, with particularly strong growth into semiconductor, quantum, and advanced materials, and from both academic and commercial customers. Increased profit and operating margin were supported by the tangible gains resulting from the improved commercial processes and operational efficiencies implemented through our Horizon Strategy. Revenue was marginally ahead of last year, with underlying growth subdued due to COVID-related disruption at customer sites and our own reduced manufacturing capacity. Disruption was most pronounced in the first quarter, with strong momentum building throughout the year as restrictions eased. This resulted in a strengthening of the order book, up 17.8% at constant currency, with significant growth in the Materials and Characterization sector and strong growth in service and healthcare.
Despite the pandemic, we continued to make good progress with the implementation of our Horizon Strategy, supporting future growth, including acceleration of our market intimacy and service transformation programs and an increased investment in R&D to 9% of revenue. Continued good cash collection in the year resulted in an improved net cash position of GBP 97.6 million. The board has proposed paying a full-year dividend of GBP 0.17 per share, in line with improved performance. With the underlying long-term growth drivers for our markets remaining robust and the positive progress with our strategy, I am confident that we will emerge from the pandemic an even stronger group with a platform for sustainable growth and further margin improvement. I'll now hand over to Gavin for the finance review.
Thanks, Ian. Starting with the income statement, revenue in the year was broadly flat, increasing by 1.7% at constant currency. Adjusted operating profit increased by 12.3% to GBP 56.7 million. Excluding currency effects, adjusted operating profit increased by 13.3% with a currency headwind of GBP 500,000. The adjusted operating margin increased by 190 basis points from 15.9% to 17.8%. Amortization of acquired intangibles of GBP 8.4 million is a non-cash charge and treated as an adjusted item. Other non-recurring costs are comprised of one-off professional fees and property-related costs and an impairment charge relating to delays in market launch on some specific development projects. We also treat the uncrystallized mark-to-market movement on derivative financial instruments that are hedging future transactional currency exposures as an adjusting item. We completed our hedging program for the financial year ending 2022 by the end of December last year.
Combined with the recent strengthening of sterling, especially against the US dollar, this results in a large positive mark-to-market movement on currency hedges of GBP 6.4 million. Financing costs fell to GBP 0.8 million as we recorded a net pension interest credit due to the pension scheme moving to a net asset position. Adjusted profit before tax increased by 12.9% to GBP 55.9 million. Statutory profit before tax grew from GBP 38.8 million to GBP 52.2 million due to growth in operating profit and the derivative mark-to-market gain. The effective tax rate increased slightly to 19.3% from 18.8%, reflecting a change in the geographical mix of profits earned. Continuing adjusted basic EPS increased by 12% to GBP 0.786. After a resilient year of trading, the board has proposed a final dividend of GBP 12.9 per share.
This gives a total dividend for the year of GBP 17 per share, equivalent to a two-year compound annual growth rate of 8.7%. Constant currency revenue increased by 3.2% for Materials and Characterization, supported by good growth for our semiconductor processing tools and scanning probe microscopes. Deliveries for our analyzing tools were hampered by COVID-related customer site access restrictions and supply chain constraints. Revenue has also been held back by delays and frustrations in obtaining U.K. export licenses. A constant currency decline of 2% in Research and Discovery was attributable to COVID-19 production constraints in our imaging and microscopy business. This was largely offset by strong growth in our cryogenic and complex magnets business. Service and healthcare revenue grew by 5.9% in constant currency, with good growth from the service of our own products. With total orders in the year of GBP 354 million, our book-to-bill ratio was 111%.
Revenue at constant currency grew by 1.2% in Europe, supported by good demand in Germany for our semiconductor processing tools. Revenue at constant currency for North America fell by 10.8%, the region being most impacted by COVID-related supply and installation issues. Order growth was strong at 6.9%, driven by demand for our scanning probe microscopes and semiconductor processing tools. Constant currency growth in Asia of 11.9% was driven by a large number of acceptances in China for our cryogenic and complex magnet systems. Orders also grew well, up 13.7%, with strong demand for our semiconductor processing tools and electron microscope analyzers. The order book at GBP 198.1 million has grown by 13.2% since last year-end on a reported basis and 17.8% at constant currency, providing good visibility for the current financial year.
We have witnessed very strong growth across all constituent businesses in Materials and Characterization, resulting in constant currency growth of 47.2%. This growth rate is skewed by strong order growth in the final quarter, combined with COVID-related delays to deliveries, as well as changes to the duty-free certificate regime in China and U.K. export license delays. We would expect to see this growth unwind through revenue during this year. Constant currency order growth in Research and Discovery of 1.6% is due to an increase in the order book for our imaging and microscopy products, partly due to previously mentioned delays to shipments. Turning to adjusted operating profit by sector, adjusted operating profit increased by 12.3% to GBP 56.7 million, equivalent to a margin of 17.8%. Materials and Characterization adjusted operating profit fell by 1.9% at constant currency, with margin dropping slightly to 13.7%.
This was attributable to a lower revenue from our higher margin imaging and analysis systems, additional investments in the sector, and a warranty provision. Research and Discovery's adjusted operating margin increased to 17.2%. Our cryogenic and complex magnet business has delivered a material uplift in profitability, supported by improved commercial practices, operational efficiencies, and a high level of customer acceptances in the year. In addition, lower discretionary costs in our optical imaging business have led to an improvement in margin. Continued focus on service revenue lifted service and healthcare reported currency margin just under 13%. Turning to the cash flow, the group delivered adjusted earnings before interest, tax, depreciation, and amortization of GBP 65.8 million. Working capital rose by GBP 2.7 million, primarily due to an increase in receivables following a high level of shipments and customer acceptances at the year-end compared to the previous year.
Cash spend on Research and Development was GBP 28.9 million, equivalent to 9.1% of revenue, with GBP 0.9 million capitalized in the year. CapEx was GBP 4 million, with investments in semiconductor processing development tools, quantum computing-related assets and infrastructure, and expenditure to increase production capacity. Looking forward, we expect capital expenditure of approximately GBP 32 million to complete the construction and fit-out of our new facility near Bristol for our plasma technology business. Costs of approximately GBP 20 million will be incurred in the financial year 2021-2022, with the remainder falling into the following year. Deficit recovery payments of GBP 15.5 million were made to the U.K. Defined Benefit Pension Scheme, including an additional contribution of GBP 8.1 million.
The scheme recorded an accounting net surplus of GBP 16.3 million as of the 31st of March, a decrease from last year due to a reduction in the discount rate and increase in the inflation rate, increasing the scheme's liabilities. Cash conversion was strong at 101%. Net cash was GBP 97.6 million at the end of March, up from GBP 67.5 million at the end of last year. As regularly presented, the business has a large exposure to foreign currency fluctuations. This chart shows the long positions for our major trading currencies, as well as the short sterling position. As you can infer from the previous slide, the group's financial results will be subject to currency fluctuations. We maintain a hedging program to mitigate currency movements up to 18 months forward from the next reporting date, covering approximately 80% of forecast transactional exposures.
In the year, we recorded an adverse currency impact of GBP 500,000 to operating profit. For the financial year 2021-2022, our assessment of the currency impact is, based on hedges currently in place and current FX rates, a reduction in revenue of GBP 18.5 million and a decrease in adjusted operating profit of GBP 2.5 million. Current rates are $1.42 per sterling dollar, EUR 1.17 per sterling euro, and JPY 1.55 per sterling yen. Looking ahead to the financial year 2022-2023, we will see the benefit from hedges currently in place rolling off. Based on current rates, this will have an adverse impact to adjusted operating profit of GBP 6.4 million. This does not affect the underlying future growth of the group and is prior to mitigating actions.
The actual currency impacts will be dependent on currency volumes and mix, as well as currency rates at the time of shipments and customer acceptances, and is therefore subject to a high degree of uncertainty. To summarize key financial highlights from the year, we've seen strong growth in orders and the order book, with revenue in the year dampened by COVID effects and the impact of export license delays and changes to China's duty-free certification regime. Adjusted operating margin increased to 17.8%, with material improvements across some of our smaller businesses, complemented by strong cash conversion of 101%. The additional contribution to the U.K. Defined Benefit Scheme will further de-risk the scheme, and on current assumptions, we expect to achieve self-sufficiency early in 2026.
Good growth in adjusted EPS of 12% leads us to propose a total dividend of GBP 0.17 per share, a two-year compound annual growth rate of just under 9%. Net cash has risen to GBP 97.6 million. Our strong balance sheet will improve future growth in the business through organic investment and acquisition opportunities. With that, I'll hand back to Ian.
Thank you, Gavin. Let me now turn to an update on our Horizon Strategy. Our Horizon Strategy has provided the resilience to enable growth and improved profitability despite the exceptional challenges due to the global pandemic, and we have continued apace with our strategic progress in the year. Profit growth and enhanced operating margin were supported by the tangible gains realized through the success of recently launched products, improved commercial processes, and our operational excellence and service programs. With travel disruption restricting the ability to meet with customers face-to-face, we developed effective Digital and Remote Sales and Marketing, reaching a wider audience and improving lead generation efficiency. In support of our customers' evolving needs, we accelerated our service and digital transformations, including the provision of new service products, increased remote support, and product connectivity.
We maintained our strategic R&D program, successfully launching products in the year, and increased our investment to 9% of revenue, ensuring a healthy product pipeline. We also continue to invest in our capabilities, business processes, and infrastructure, including the commissioning of a new facility for our Plasma Technology Business. Moving to sustainability, we remain passionate about our sustainability agenda, which is driven by our purpose, values, and culture, recognizing the role we play in society and the world around us. In line with our purpose, our products drive a step change in enabling a greener economy, improved health, increased connectivity, and leaps in scientific understanding. We strive to create positive outcomes for all of our stakeholders through a focus on how we do business and our operational impact on the environment.
We have aligned with the three UN Sustainability Development Goals identified on the slide, where we have the most potential to influence and shape a positive future. Whilst our operational impact on the environment is relatively small, we have significantly reduced the CO2 emissions from our own facilities by moving to renewably sourced electricity and also reduced the amount of waste going to landfill. Through the pandemic, we have become more connected with our employees, resulting in increased engagement scores, and we recognize the importance of diversity and inclusion, focusing on creating an environment and culture where difference is valued and everyone can contribute to their full potential. Looking at our response to the coronavirus, our priorities throughout the pandemic have remained the health and well-being of our employees and the support of our customers and strategic partners.
We took swift action at the start of the pandemic to implement a hybrid workplace model, enabling us to maintain business continuity and keep our employees safe. By enabling our teams to work efficiently and securely from home, we were able to maintain progress across our strategic priorities and product developments. Through embracing new working practices, we were able to further exploit synergies across the group. Moving forward, we will build on the new ways of working and adopt a more flexible but structured workplace model. Our robust performance in the year is testament to the agility and commitment of our employees. Moving to our operations review and starting with the group performance. As previously mentioned by Gavin, orders for the group were up 6.7% at constant currency, supported by growth from academic and commercial customers.
Revenue was subdued by COVID-related disruption at customer sites and to our own manufacturing capacity, and predominantly in the first half. Positive momentum quarter on quarter led to constant currency revenue growth of 1.7%. This resulted in a book-to-bill ratio of 111% and constant currency order book growth of 17.8%. Adjusted operating profit growth of 12.3% and an uplift to operating margin by 190 basis points were supported by the realization of gains through our Horizon Initiatives. Our proactive engagement across the full technology cycle has supported our performance through the pandemic and positioned us well to benefit from each wave of commercialization and technology disruption. Looking at our end markets, we target a broad and diverse range of attractive end markets and industrial sectors with robust long-term growth drivers. COVID-related disruptions impacted individual application segments and regions by varying amounts, subduing both orders and revenue in the year.
Order growth was supported by strong demand from buoyant semiconductor, quantum, and advanced materials markets, supported by growth in life science. Overall order growth was partially offset by a significant reduction from researchers in fundamental science and a subdued energy and environment segment. From a regional perspective, good order growth across Asia and North America was partially offset by a small decline in Europe, where customer disruption has been most pronounced. Our customer-centric approach and tailored product launches enabled expansion into new applications, further supporting order growth in the year. Moving to our individual sectors and starting with Materials and Characterization, the sector represents 47% of group revenue, providing products for the imaging and analysis of materials, as well as the fabrication of semiconductor devices, with commercial customers representing 56% of revenue. Orders for the sector increased 14.4% at constant currency, with growth evenly split across academic and commercial customers.
From an end market perspective, we saw strong growth from the main segments of semiconductor and advanced materials and the growing quantum and life science areas. However, energy and environment markets were subdued in the year. COVID disruption subdued revenue growth, supporting a 47% constant currency increase in the order book, providing greater visibility into the current financial year. The disproportionate delay in shipments of our higher margin imaging and analysis systems, combined with an increased investment in the sector, led to adjusted operating profit and margin being slightly behind previous year. Looking at end markets and starting with semiconductor and communications, which remains a significant focus for the sector, the rising importance of improved energy efficiency, increased connectivity, and faster data communications has elevated the role of semiconductor chips in the global economy, driving both increased demand and higher performance requirements.
This supported strong order and revenue growth across our portfolio of compound semiconductor etch and deposition systems, underpinned by our strategic focus on improving the key processing steps that determine end device performance. This included sales to commercial customers developing and manufacturing the optical devices used within hyperscale data centers and fiber optic communication systems in support of the exponential growth in data volumes and expanding digital services. As previously mentioned, we have commissioned a new purpose-built facility to house our Plasma Technology Business with state-of-the-art facilities and increased production capacity. The strong silicon chip and consumer electronics market drove increased demand for our imaging and analysis solutions. Here, our systems are deployed in applied R&D, as well as in quality control in high-volume manufacturing, for example, in the inspection of wafers and devices to confirm structural integrity down to the nanoscale.
Within the energy and environment segment, orders and revenue declined due to subdued markets, including forensics and environmental monitoring, which more than offset strong growth across battery applications. Moving to advanced materials, these are the building blocks of modern society, making up the infrastructure, equipment, and goods that we all use every day. The drive for stronger, lighter, and higher-performing materials and increased productivity underpins growing demand for our products. We help our customers enhance the value and utility of their offerings through enabling the measurement and control of materials down to the nanoscale. This included growth to customers developing advanced steels and super alloys, as well as advanced polymers for use in diverse applications, including battery membranes, displays, and tires. Growth in these areas was partially offset by ongoing weakness within automotive and aerospace.
Within the Healthcare and Life Science segment, our tailored solutions for the development of biocompatible medical implants and pharmaceutical quality control supported good order growth. Moving to our second sector, Research and Discovery, this sector represents 35% of group revenue and provides advanced solutions that create unique environments and enable the imaging and analytical measurements down to the atomic and molecular level, with academic customers representing 74% of revenue. Revenue declined 2% at constant currency due to the significant COVID-related disruption in the first half, despite growth in most of our markets in the second half of the year. Growth from academic institutions was more than offset by disruption to commercial customers. Within the sector, buoyant end markets drove significant order growth in quantum and advanced materials markets, with good growth into semiconductor and an inline performance in Healthcare and Life Science.
However, orders for research and fundamental science were significantly down, reflecting continued subdued activities from these customers. Substantial improvements in profitability and margins were supported by the realization of tangible gains in the year from previously implemented Horizon Initiatives. Looking at end markets and starting with Healthcare and Life science, the long-term fundamental market drivers of improving the health and well-being of society remain robust, driving the need to better understand fundamental disease mechanisms at the cellular and molecular level and for the development of new treatments, therapies, and personalized medicines. As customer restrictions eased, positive momentum resulted in orders ending in line with previous year, with second half year-on-year growth. Our products were used in the global fight against coronavirus, helping researchers to study the virus and its mutations, as well as the use of our scientific cameras in diagnostic testing systems.
We also had growth into cancer research applications that saw reduced orders from central research laboratories due to site closures, as well as the reprioritization of work and resources towards COVID-related initiatives. Within the Research and Fundamental Science segment, customer site closures and delayed funding, more than offset growth elsewhere within the sector. Within Quantum Technology, the market is in a state of acceleration, with significant scientific and technical breakthroughs bringing forward the timeline for practical quantum computers and sensor-based systems. This has supported strong order revenue growth, with increased government and corporate investment. Whilst many experts believe we are still a number of years away from the disruptive quantum computers that could revolutionize end markets from drug discovery to financial services, governments and commercial organizations are using existing quantum computers in applications where they already outperform conventional systems.
We have made good progress with a consortium to build and deliver the U.K.'s first commercial quantum computer, which will be available as a cloud-based service. In the advanced materials segment, strong order and revenue growth reflected ongoing demand for our key enabling technologies to investigate the fundamental properties of exotic materials such as graphene. Moving to our final sector, Service and Healthcare, this sector represents 18% of revenue and comprises the support services related to our own products and the service of third-party MRI systems in Japan. Strong order and revenue growth was driven by increased demand for services related to our own products, with an unchanged demand from our MRI customers in Japan. Our increased local provision of services, combined with enhanced digital and remote offerings, supported growth in orders, revenue, and profit, and an uplift in operating margin.
To meet the evolving needs of our customers, we accelerated our service transformation, delivering higher value-tailored products whilst improving our delivery capacity through remote services and better leveraging synergies across our global footprint. Whilst we're at the early stages of this transformation, providing an increased portfolio of services to support our customers throughout the lifetime use of our systems will form an increasing part of our ongoing Horizon Strategy. Finally, moving to our summary and outlook, we have seen strong order growth, with revenues impacted by COVID disruptions leading to an increase in the order book. Tangible gains in the year from our Horizon Strategy have supported increased profit and enhanced margin. Progress in the year reflects the outstanding agility and engagement from our employees to adapt to new ways of working, whilst driving forward with our strategy for increased end market focus on operational effectiveness.
Our robust performance, strong order book, and breadth of attractive end markets demonstrate the resilience of our business model, positioning us well for good progress in the year despite anticipated currency headwinds and the ongoing uncertainties as global economies look to recover from the pandemic. That concludes our full-year results presentation.