Year	% of revenue
1990	42.79087525054882
1991	45.10313745883169
1992	45.13038445134954
1993	44.21234243997034
1994	45.50505611734637
1995	45.6822482304296
1997	45.472209066511226
1998	45.10867067959381
1999	41.809487130111044
2002	40.74084836514671
2003	43.25306644830386
2004	41.30567431387831
2005	38.41084248404448
2006	37.91861812504072
2007	41.339370322823314
2008	40.21563986080016
2009	39.91198118239066
2010	46.20946798389172
2011	46.75645540230364
2012	46.517309726324626
2013	44.67376597304338
2014	44.19174307425172
2015	45.05303742213171
2016	44.8225074444098
2017	44.4238148576342
2018	44.92398827107525
2019	44.69697120487871
2020	38.77910556550914
2021	45.09331634404777
2022	43.867470088470014