Year	% of revenue
1990	10.219136472119764
1991	10.964108340586758
1992	16.65620034183927
1993	18.610347827287665
2001	29.276349269988234
2002	29.047588745032783
2003	22.147782020883707
2004	13.918337011919688
2005	12.069815411844601
2006	12.028437396438797
2007	9.614324752654127
2008	12.053713598723457
2009	15.175251143622138
2010	16.247689217892894
2011	12.456195351812784
2012	15.491478303102316
2013	23.83448606232947
2014	30.297521017349933
2015	30.91616344553032
2016	35.76756427251068
2017	34.1914288399151
2018	33.2134913452379
2019	37.035221609975785
2020	44.61381124140827
2021	47.82346175470393
2022	47.2703409932749