Year	% of revenue
1990	21.701495654595455
1991	22.36424951030876
1992	32.39032061362688
1993	27.555739251818984
1994	25.4459377594292
1995	22.220387349063333
1996	22.410712594622236
1997	19.66283615841558
1998	20.40187508236431
1999	18.09371073916039
2000	17.181298891973114
2001	14.520921088039366
2002	13.210295260495206
2003	10.465406464002164
2004	11.250141593738501
2005	11.458877284595301
2006	10.424071559733525
2007	9.25343069369256
2008	6.4768698294783045
2009	6.420861718127931
2010	6.125206425461642
2011	5.301169212582427
2012	5.650634113527095
2013	5.643536847954435
2014	4.503550002751941
2015	4.8967820725983255
2016	4.399117347516126
2017	4.098206108926359
2018	3.612378251756873
2019	3.567053118914667
2020	3.9038825420762846
2022	2.6105003365492485