Year	% of revenue
1995	39.06978672249052
1996	33.26405545611723
1997	34.16402032660654
1998	36.06910942047995
2002	43.07440695220755
2003	45.6780250204408
2004	48.69625951082895
2011	55.57162216283468
2012	55.40508210801032
2013	54.17478974215769
2014	55.58132901056939
2015	54.62769396154405
2016	55.92681300772858
2017	53.2947888187206
2018	53.132719246821495
2019	50.69292952410552
2020	51.90149985854998
2021	45.59420808622165