Year	% of revenue
1990	4.2242910186729805
1991	4.200623984246177
1992	3.8245614035087723
1993	3.2447767924244704
1994	3.707679952660721
1995	3.555365764624042
1996	3.4282782626766415
1997	3.7139470564994075
1998	3.8860373836906104
1999	3.794607610926891
2000	3.7723729025042863
2001	3.5107994109032954
2002	0.940456482820096
2003	0.017944098854392434
2006	2.940491785167532
2007	5.246263113136833
2008	7.929862589059275
2009	9.610703919422905
2010	12.348415501162897
2011	9.427992129838712
2012	2.563701134339552
2013	8.801449740312666
2014	9.666381677450648
2015	8.528615346631414
2017	0.03178521753792862
2018	0.055301365732213184
2019	0.10647696791329152
2020	3.303875505365155
2021	1.0985400613123724
2022	0.00947486337250939