I am delighted to introduce another set of impressive results. Group revenue has grown by 46% to £111.4m. Gross profit has increased by 17% to £50.7m and adjusted EBITDA was £13.4m, 17% up on compared to the previous year. We have had another period of strong cash generation, with over 86% of adjusted EBITDA converting to adjusted cash generated from operations. It has been four years since our IPO, during which time the Group has performed very well.
Throughout this period we have delivered a 4 year revenue CAGR of 27%, 4 year gross profit CAGR of 16% and a 4 year adjusted EBITDA¹ CAGR of 17%. Our cash generation over this timeframe has been consistently strong, generating more than £42m adjusted cash from operations¹ and converting over 96% of adjusted EBITDA¹ to cash.
The year to 31 March 2018 has seen us further consolidate our leading position in the UK digital communications market. We hold a dominant position in banking and mobile operator verticals and now hold leading positions in utilities, logistics, small and medium sized enterprises and, following the acquisition of Healthcare Communications, healthcare verticals.
We have maintained our track record of organic growth despite expected challenging conditions in the Middle East & Africa region. Our businesses in the Europe & Americas and India & South-East Asia regions have performed very well. We have also added two more successful acquisitions, bringing Sumotext and Healthcare Communications into the IMImobile family during the year.
It is equally pleasing to report that our earlier acquisitions continue to progress well. The Group has benefited from revenue synergies created as a result of the combinations that we have made. Textlocal continues to go from strength to strength in the UK and in India. IMImobile South Africa (formerly Archer Digital) has won its first significant recurring revenue contract delivered using IMImobile products into a major banking client. IMImobile Intelligent Networks (formerly Infracast) has also successfully sold IMImobile intellectual property into its customer base.
The Board continues to monitor the status of Brexit and at this time we do not think it will have a material impact on the Group’s global operations.
The Group has continued to innovate and invest in new capabilities, including AI and automation. We believe our market-leading software and solutions are as relevant as ever for organisations looking to automate and digitise their customer interactions. We will continue to seek opportunities to accelerate the distribution of our intellectual property.
I would like to extend my thanks to all members of the growing IMImobile family for another year of success and commitment. Our strategy is unchanged and the attitude and capabilities of the teams across the world leave me confident of our potential in the coming years.
The new financial year has started well with prospects for growth across all regions. Our evolving products and solutions leave us very well positioned to expand our footprint within existing clients and add new logos to our already impressive customer list.