Year	% of revenue
1990	27.934585785423266
1991	28.05707901685964
1992	29.05628726602335
1993	28.90873813425683
1994	30.003657190624534
1995	32.85105100312952
1996	33.68569798092339
1997	35.50274104430004
1998	39.73867074075842
1999	38.79730729740955
2000	39.08680749117998
2001	39.00429643104673
2002	39.032514889158485
2003	38.22360732372419
2004	39.24143475746506
2005	39.64320745463463
2006	38.64838154757145
2007	40.754873330170206
2008	41.1196178694791
2009	38.76551410348761
2010	40.49980173168129
2011	42.070084074409166
2012	42.08176744052009
2013	41.92656732690199
2014	41.163235518558515
2015	41.34354136181419
2016	41.95462498850049
2017	41.46922239646386
2018	36.52747573625793
2019	37.13246648854303
2020	36.61459783067348
2021	35.18367839171286
2022	34.91039005784372