Year	% of revenue
1984	7.609231308938131
1986	20.257382511777546
1987	18.441479600987872
1988	19.40249934912783
1989	17.647588817679495
1991	30.127935401344608
1992	32.69524435281338
1993	33.02283315330051
1994	29.087232268084286
1995	27.996202085247745
1996	26.2767706326628
1997	29.61650660846854
1998	27.635318655848952
1999	30.177049831625247
2000	26.353467800586067
2001	27.504600581392847
2002	26.840904319938048
2003	28.201627437059688
2004	31.29197011255084
2005	30.988760664474675
2006	29.744153188727985
2007	30.291347701276578
2008	28.237028706480082
2009	28.02647042368948
2010	24.03794244248825
2011	25.09267938094979
2012	27.452994469021437
2013	27.895034336620395
2014	30.54231130872368
2015	30.042020638077183
2016	28.642370984856598
2017	31.016090184371297
2018	30.79275309909641
2019	32.32659056079616
2020	30.85863583830224
2021	29.82436477580461
2022	31.36912194168069