Year	% of revenue
1990	6.764553845418352
1991	9.70366066240558
1992	13.451190476190481
1993	16.921883951495317
1994	11.574416216371855
1995	7.783018867924528
1996	12.11754207037226
1997	19.656129224061043
1998	11.567730352695895
1999	30.93220338983051
2000	41.046969290508976
2001	58.65405667424286
2002	56.87718564640794
2003	67.1206678037836
2004	59.52736579626063
2005	70.53238411042535
2006	62.005256306985345
2007	60.31215242304946
2008	53.15647014169349
2009	61.97836603587579
2010	59.56852005601061
2012	53.07061668166494
2013	47.77027663591788
2014	46.7013251594389
2015	41.02563846227796
2016	39.1573534810853
2017	30.788744946470796
2018	33.39034463384466
2019	36.02115998506984
2020	37.58792232258231
2021	38.21218539799056
2022	35.0834107389455