. 2018 2017 2016 2015 2014
Group Revenue (£m) 872.0 752 597.5 486.6 430.9
Underlying Group gross profit margin 58.1 60.2 61.6 60.9 59.7
Underlying Group operating profit margin 11.5 11.9 12.2 13.1 14.3
Underlying Group profit before income tax (£m) 97.0 87.0 72.4 63.2 62.0
Underlying basic Earnings Per Share (EPS) 93.6 84.5 70.9 59.1 58.0
Year-end net cash 75.8 65.4 100.7 67.6 86.2