Year	% of revenue
1992	26.577636639271613
1993	26.849619499976207
1994	27.84388664220478
1996	27.034440719292895
1997	28.21210771745556
1998	26.39064122700861
1999	28.171760619864028
2000	30.2209723575052
2001	26.090212831332348
2002	27.82777164140222
2003	32.14952843832401
2004	28.20980842426617
2005	33.81532113261114
2006	36.656763253717514
2008	32.00456022609518
2009	32.83293949505896
2010	30.632618029201776
2011	36.237808654522446
2012	33.84524491101992
2013	35.24071951476202
2014	32.586347316696745
2015	31.474029418679628
2016	34.272878914928974
2017	30.91337517999357
2018	31.640169102358374
2019	28.39044401855299
2020	31.14123448411285
2021	31.083319956374588
2022	27.571752368581855