Year	% of revenue
1994	30.45169521204743
1995	33.92186934479715
1996	26.783406518867586
1997	40.28324363840433
1998	37.30983282342101
1999	39.16282958382
2008	12.647813870752561
2009	17.812246692403864
2010	13.553220373070541
2011	12.091937723418713
2012	13.625043681353924
2013	14.861605604685884
2014	17.608358640022086
2015	23.6737853222746
2016	22.40241891148983
2017	19.489615590395434
2018	17.738615728832002
2019	18.04622880444079
2020	23.03827247718834
2021	18.987997306838103