Year	% of revenue
1981	4.822456813819578
1982	5.01481650330522
1983	7.223942208462332
1984	9.473094170403588
1985	9.058845368479673
1986	11.700725115359262
1987	10.932768019382193
1988	2.468666919863274
1989	0.23824994585228504
1990	0.20797540464779818
1991	0.9714285714285713
1992	2.151698330454807
1993	2.186468646864687
1994	2.081120231772091
1995	0.18959168867014264
1996	0.1989809333627067
1997	0.3721152122447411
1998	0.3168816193064718
1999	0.38662055801340706
2000	0.3890137468849005
2001	0.41826809044448804
2002	0.44188882052531464
2003	0.4586449987160109
2004	0.5749833055224853
2005	0.6568564442690744
2006	0.6528940888606161
2007	0.7248751045770232
2008	0.6659583057073163
2009	0.7043097800149828
2010	1.0948024248644763
2011	1.2051404388366957
2012	1.3336154554058535
2013	2.081549956602077
2014	2.052722136348741
2015	2.0369898501652255
2016	2.256488048226462
2017	2.572744932952741
2018	2.755946302346417
2019	2.9825106899664884
2020	2.930170990300589
2021	3.2006996022900593
2022	2.098221271060573