Year	% of revenue
1990	8.007766122386267
1991	7.227614896988907
1992	4.350294259249944
1993	3.467259571226954
1994	3.3557643307940572
1995	5.409437919115391
1996	3.64068232151612
1997	1.960597242761055
1998	1.4215646938383464
1999	0.9034658450136943
2000	2.073793906182914
2001	1.5948265383025795
2002	5.604680222651369
2003	5.967935152101702
2004	6.1930970041888465
2005	5.656847744103656
2006	5.370970377044434
2007	5.33694263211379
2008	5.19201626807354
2009	4.643962018839018
2010	4.492440055700393
2011	4.665429286397363
2012	4.543147811953914
2013	4.367416761210583
2014	4.247855112619417
2015	4.474044621607278
2016	9.885911898784636
2017	6.874882127688729
2018	5.151736413677472
2019	5.0179256996608865
2020	7.727349413543211
2021	7.037307988283444
2022	5.487093703240337