Year	% of revenue
1993	18.80863977800354
1994	16.31557673688465
1995	14.913572824289794
1996	12.914408375048101
1997	13.9767768204924
1998	13.372743634734283
1999	13.036019852455642
2000	12.79680250220005
2001	18.350939068029934
2002	18.727350508939587
2003	17.671692045281773
2004	18.89786377482251
2005	18.206571956571956
2006	18.241260928034013
2007	18.309947588347562
2008	16.91730451274455
2009	15.535017245971176
2010	14.76883738851049
2011	14.755006788415953
2012	14.681379702596109
2013	14.585689914997255
2014	15.362854605448414
2015	14.901991467601686
2016	15.652981857396927
2017	16.143590425290864
2018	16.62092829018017
2019	16.777935714855435
2020	16.74776449255436
2021	14.370886208662684
2022	15.012059452005385