Good morning, everyone, and welcome to our FY 2023 trading update. As usual, I'm joined by our CFO, Andy Beach. The group delivered a resilient performance for the year in line with expectations, despite a challenging macroeconomic backdrop. This reinforces our confidence in our strategic focus on STEM and contract, provides a robust business model through this cycle. Following a record prior year, group net fees remained relatively consistent, down only 4% for the year. Our business grew 1% year-on-year and now represents 82% of group net fees. Due to the resilient financial performance, we are pleased with the progress we're making with our Technology Improvement Programme, which continued to be on track and on budget. We are delighted that the rollout of our new end-to-end integrated platform is now complete across the US business. The platform is live, and it's working.
We already have nearly 2,000 contractors onboarded and using it to submit time sheets, while to date, we have issued over 10,000 invoices, reflecting nearly $50 million of revenue. This really is a significant milestone for the program team and the group. We are already realizing some early positive results in terms of immediate process improvements, but as we have said before, the wider benefits around efficiencies and scaling will be evident with time as the program progresses and the platform develops richer functionality. The sequenced rollout across the rest of the group is progressing in line with stated plans, and we look forward to updating you as the program continues. We continue to believe that the transition to a digital-first approach is key to delivering a higher value proposition for SThree.
The implementation of a unique end-to-end technology platform, together with innovative ways of working, will clearly differentiate us. Overall, we believe we are uniquely positioned to win in a changing world with global mega trends support. With that, we'll hand over to Andy, who will take us through the numbers.
Thanks very much, Timo, and good morning, everyone. Net fees were down 4% on a constant currency basis against a record prior year comparator and a challenging global macroeconomic environment. This performance includes the impact of markets that were restructured in Q4 last year: Ireland, Singapore, and Hong Kong, in line with our continuous market investment model. Excluding these, our underlying net fees would have been down only 3%. Our contract business now represents over 80% of group net fees, and I'm pleased to report that this part of our business delivered year-on-year growth of 1%. This performance was supported by strong contract extensions throughout the year and reflects growth in two of our three main skills, with both engineering and technology up 18% and 1%, respectively, with life sciences down 14%.
Permanent net fees declined by 22%, resulting from challenges within life sciences and softer market conditions across all of our regions, together with our targeting investment towards contract, particularly in the U.S. and the U.K. Average permanent headcount was down 17% year-on-year. So let's take a look at what's driven the performance over the year, starting with the regional perspective. DACH net fees declined 3% year-on-year. Germany, our largest country in the region, saw contract down 1% and overall net fees down 4%, with growth in engineering offset by declines in both technology and life sciences. Now, as a reminder, in Germany, we have a greater exposure to SMEs, who are more sensitive to the macro environment than our enterprise clients. In the Netherlands region, net fees were up 6%.
The Netherlands itself, our largest country in the region, saw contract up 4%, with overall net fee growth of 3%, driven by engineering and technology. Spain, although currently a small part of the group, saw strong year-over-year growth of 82%, driven by technology. Rest of Europe net fees were down 4%. Contract, which represents 95% of net fees for the region, grew 3%. The U.K., our largest country in the region, saw contract up 1%, while overall net fees were down 3%, with growth in engineering offset by declines in both technology and life sciences. In the U.S., against a particularly tough market backdrop, we saw net fees decline by 14%. Contract net fees, which now account for 88% of the total, were down 4%.
Now, our U.S. business is more heavily weighted to life sciences than the rest of the group, and the performance for the year is impacted by that sector, which was down 16%, in line with the wider life sciences market conditions. This was partly offset by engineering, which was up 19%. Finally, in the midyear, net fees for the region were up 3%. However, the performance includes the impact of restructured markets. Excluding these, our net fees for the region would have been up 20%. Japan, which represents 45% of the region's net fees, up 6%, driven by engineering and life sciences, while the UAE had an exceptional performance for the year, with net fees growing 41%, driven by engineering. From a skills perspective, technology, our largest discipline, declined by 2% year-over-year.
Now remember, when we talk about technology, we're referring to placing people with skills in technology across multiple industries. Also, to remind you, on the contract side of our business, we saw an increase in net fees from tech skills. Engineering grew by 17%, with continued strong demand across all regions, driven by energy and particularly renewables, which were up 28% year-on-year, and now represents 10% of group net fees. While life sciences declined 21%, primarily driven by the global market conditions in that sector, together with tough comps, but it's worth noting that we are still trading comfortably above pre-COVID levels. Moving on to headcount. Average headcount for the year was down 10% year-on-year , with period-end headcount declining by 15% from the end of FY 2022, in part through careful management of natural churn.
This also includes the impact of the restructured regions, and excluding countries, our period-end headcount declined by 13%. In line with our strategy, while closely monitoring and taking the evolving market conditions into account, we're maintaining our disciplined and focused headcount investments in the markets and skill verticals that provide the best growth opportunities, and where we can generate the strongest returns as the market recovers. Productivity for the year was down only 2% year-on-year, with the impact of a strong prior year comparator on net fees, partially offset by the 2% reduction in average headcount. Pleasingly, productivity remains significantly ahead of pre-pandemic levels. The contract order book of GBP 184 million is down 3% year-on-year, reflecting the prolonged market uncertainty. However, it continues to provide good visibility of over four months worth of net fees.
And finally, we have a strong balance sheet, with net cash of GBP 83 million at the end of the year, up GBP 18 million year-on-year, as we continue to benefit from the anti-cyclical nature of our working capital model. With that, I'll hand back to Timo.
Thanks, Andy. We're confident in this case that we're focused on. Our teams have continued to execute well, filling essential in-demand roles, and we have made good progress against our clear strategy. Through our Technology Improvement Programme, we're progressing to the next stage of our growth journey by embedding a digital-first approach across the organization from a unique end-to-end IT platform, through to innovative ways of working. We look ahead to our next regional deployment in Germany, commencing in early 2024. We have great team in place and are confident in our approach. In line with the industry, we've continued to see a softer trading environment, given the macroeconomic uncertainties. Despite that, over the past year, we have seen strong extension to performance from our existing customers, and as always, December and January is an important period for contract extensions.
Our STEM and flexible talent provides resilience, and while some in the industry see this downturn as a crisis, we have always seen the opportunity to both revolutionize our processes and technology while driving our market investment model to take full advantage when the market improves. Thank you all once again for joining us this morning. I would like to wish you all a restful break. We definitely will need it over the holiday season, and you will hear from us again in the new year when we publish our full year results on the thirtieth of January. So watch out. Thank you, guys.
Thank you.