Year	% of revenue
1990	0.9325532076043324
1991	0.8429423459244533
1992	0.638630548674004
1993	0.47524314765694076
1994	0.3251189746972624
1995	0.25514920681877007
1996	0.3341182460383122
1997	4.53620317573648
1998	2.5358288294425204
1999	2.565677685104931
2000	2.5109827133405926
2001	2.327244163758988
2002	1.2337745911306572
2003	0.9839838983570136
2004	1.9576719576719577
2005	2.032472997785491
2006	2.2958372902865136
2007	1.9649097398028534
2008	2.031499430583391
2009	1.9247784812223272
2010	0.49191239284348554
2011	0.5235828484951162
2012	1.0202413484643853
2013	1.0545047685817548
2014	1.1085902761745352
2015	1.2241484397518092
2016	1.0319759275366627
2017	1.2540193214672
2018	0.6790219347801828
2019	0.9443506869132466
2020	1.5559523818566154
2021	1.0985400613123724