Year	% of revenue
1991	3.440934065934055
1992	10.738544940119413
1993	8.712218054031947
1994	9.545356987596525
1995	6.370142679904542
1996	6.509935828888981
1997	6.305607553381305
1998	5.306730836388231
1999	6.055597544694137
2000	5.213723206000759
2001	4.135951282460067
2002	2.5082360188125996
2003	1.994046144907451
2004	1.6838545966839407
2005	1.55151322951567
2006	1.4913713685474317
2007	1.3498935944648551
2008	1.4434186447868398
2009	1.4418137473890407
2010	1.413596278545359
2011	1.5019911139859259
2012	1.493807388124833
2013	0.8545877090496881
2014	0.000188106419447097
2015	9.158617291492343E-05
2016	0.00020041599861333795
2017	4.646010641016283E-05
2020	0.0003025645220083201