Year	% of revenue
1995	10.947830953219889
1996	17.875375446932825
1997	33.89836703952618
1998	36.58553006346331
2002	16.451241686009137
2003	17.86486673249766
2004	15.489994211655599
2011	12.986133562034347
2012	13.180952862680542
2013	14.045016773217453
2014	11.270112693271727
2015	10.522321756560295
2016	9.715191572094641
2017	7.73970302969854
2018	8.5813935058396
2019	8.066556475391454
2020	8.525820720312227
2021	6.505614909577849