Year	% of revenue
1991	39.326220720282905
1993	31.154215479162666
1994	32.17282404508454
1995	33.26420590831171
1996	32.64868004823933
1997	32.46673709394202
1998	34.3872666024537
1999	34.73584465483787
2000	33.28240003256959
2001	36.54302790430535
2002	36.723843653060776
2003	34.85996274375431
2004	33.30189906573786
2005	33.24864125245578
2006	33.078797028338315
2007	33.74647565879862
2008	33.17011501307714
2009	32.19549023239121
2010	33.56388072503691
2011	34.638823924483404
2012	33.64612075750815
2013	33.527129582623054
2014	32.90340969436081
2015	33.66528969319199
2016	34.14911061391518
2017	35.012640448613325
2018	33.774485254426644
2019	33.24828231930446
2020	33.35499916602648
2021	33.39127513981952
2022	32.57375974609178