Year	% of revenue
1992	4.789522918615528
1993	2.8222013170272815
1994	5.005744296733957
1995	8.753596849916704
1996	5.235525740119586
1997	5.6184080421885305
1998	6.620929177054076
1999	5.40196464377882
2000	12.708595428106802
2001	10.22294725394236
2002	11.50261822573522
2003	9.577183442459217
2004	12.401756341963633
2005	16.31882559851987
2006	26.124989164211204
2007	29.094286582472506
2008	11.086940088527538
2009	28.39209645172856
2010	39.87853519449309
2011	47.06517778884539
2012	43.774986698069426
2013	40.80510861698314
2014	42.76315525458227
2015	52.063314249562474
2016	58.03613179158382
2017	61.922973642912574
2018	62.4640610433461
2019	67.36105129142516
2020	64.53583678377889
2021	61.13697950196191
2022	57.129308785108634