Year	% of revenue
1984	0.12714558169103624
1988	0.039738858927050806
1989	1.14342530449913
1990	2.917078683429863
1991	1.9316407379561622
1992	3.1401731053409327
1993	2.327923894795747
1994	7.215026335839932
1995	5.588598361575581
1996	4.659546969593905
1997	4.396705738812149
1998	2.1106107574756603
1999	1.2336826084411403
2000	1.0297629747566832
2001	0.9035361361612698
2002	1.3165762193946415
2003	2.40739373368042
2004	2.1237476590846223
2005	3.8838988713188543
2006	2.8401017307275227
2007	2.756273996867144
2008	9.406088936341446
2009	8.406821764121872
2010	6.530876741194653
2011	6.434830617125574
2012	5.750879011620033
2013	8.631858577933228
2014	5.585737900228662
2015	5.755923514542456
2016	5.001746196076424
2017	4.672680195901855
2018	4.035877957306175
2019	3.438671851870861
2020	1.515961193467371