Year	% of revenue
1995	19.511233740638552
1996	16.293322062552832
1997	17.410244855039807
1998	19.71731448763251
1999	19.834915138961883
2000	21.48637866180326
2001	19.14552110266088
2002	20.118459490606323
2003	20.064750473783953
2004	19.198679337884265
2005	18.489813994685562
2006	20.36865843068045
2007	22.325667808926138
2008	33.74010613017921
2009	32.83905532034432
2010	32.29849770204727
2011	36.65938595951517
2012	36.39070129797861
2013	35.789088819827114
2014	33.13221280467366
2015	33.50385741986056
2016	33.1426224497593
2017	30.94428261125798
2018	33.53649810164412
2019	32.431525491979926
2020	33.531283808861964
2021	31.022559506850733
2022	35.57988525419313