Year	% of revenue
1992	0.6265157639450283
1993	4.188005947464067
1994	2.639564046196241
1995	1.6370456697501639
1996	3.1656726148793854
1997	10.937773353844298
1998	6.179227680088227
1999	8.502251145233274
2000	5.999432740129019
2001	4.53119275405835
2002	4.970933755136332
2003	3.060444294760594
2006	1.1860753896249627
2007	0.9688618669373164
2008	0.9744722218268844
2009	1.5579067800383433
2010	1.39725990977023
2011	0.9391566201062089
2012	2.7286116550825548
2013	4.984125750335615
2014	8.667212632987743
2015	13.470262661631422
2016	18.266798069235954
2017	16.034792793399927
2018	10.936260630466538
2019	6.890697969088435
2020	8.686903327590608
2021	6.168195157771453