Year	% of revenue
1990	13.94444882708568
1991	17.607932226072187
1992	9.261987782817291
1993	10.059524326766828
1994	11.548498969659693
1995	11.15621832761427
1996	11.47809102461524
1997	7.5212305289998245
1998	10.608348392154362
1999	10.799096854958467
2000	10.754256749980069
2001	11.60538917251058
2002	10.578940788073139
2003	10.17509167133378
2004	10.890187022775109
2005	11.58379767240241
2006	10.748904733270336
2007	11.429381143445251
2008	11.17627643638764
2009	12.645323477083378
2010	12.957250902291623
2011	12.480501661915598
2012	12.904047401960653
2013	13.148987177662477
2014	11.670689925197362
2015	13.401981400232263
2016	12.550410247551728
2017	12.516237671833705
2018	12.79505881589059
2019	13.693050803984322
2020	15.23617571648507
2021	13.430978345015285
2022	12.669868306677293