Year	% of revenue
1990	12.389647085822475
1991	16.59838894205011
1992	19.411687596675666
1993	10.212984123949635
1994	9.415885658288419
1995	5.984353317939798
1996	3.1404433567091825
1997	6.416199954766038
1998	6.76853787730635
1999	4.985312589632765
2000	6.169555076082736
2001	10.031723973396058
2002	4.538948685506906
2003	4.01961801114115
2004	3.627368781994029
2005	3.787423898396864
2006	4.349454514216991
2007	3.8670703876616503
2008	3.796514924552094
2009	3.5799475079857985
2010	3.929163269614133
2011	3.361081077693371
2012	3.5806706889093007
2013	2.738634267341268
2014	6.307835870516033
2015	5.142480195647908
2016	6.377339597447248
2017	3.683474815341128
2018	3.8134583215571514
2019	4.165484019465084
2020	3.252382776262323
2021	2.9919168596313455
2022	3.0302200783543767