Year	% of revenue
1990	1.7786109460015544
1991	3.0414894470748735
1992	6.108455395593216
1993	9.134123593477344
1994	7.88477117229667
1995	7.5401447780995845
1996	7.230721707704873
1997	6.840607217766485
1998	5.368637948611548
1999	2.957505233316828
2000	2.2469677402633
2001	1.7840137173182373
2002	1.7300843141527769
2003	1.8026037144565914
2004	1.9736032621935844
2005	2.3294359727584495
2006	2.5614884139223504
2007	0.011072555646905863
2008	0.009569103605970485
2009	0.011493701306787386
2010	0.01441106698358785
2011	0.011863402625191253
2012	0.0649369853455285
2013	0.04217783660056502
2014	0.05335929951063779
2015	0.05076728538852738
2016	0.04468179730992349
2017	0.041176352557735066
2018	0.04116238006569736
2019	0.03087220091929007
2020	0.02655027144080763
2021	0.040387429422100767
2022	5.717956881142245