Year	% of revenue
1990	23.04553264604811
1991	23.798756359525157
1992	31.612390786338363
1993	26.906474820143885
1994	28.162992651970608
1995	27.02185078784713
2003	20.48016082831229
2004	16.444457642789292
2005	17.65473859118153
2006	11.90842101115183
2007	20.128565238492957
2008	16.814074216496827
2009	18.87475940296115
2010	39.73330206284898
2011	45.275322183292516
2012	50.42817704917325
2013	52.74702250593685
2014	46.632055830699
2015	49.1514666844012
2016	41.6684835227652
2017	44.91268786545135
2018	42.513312330309674
2019	40.45878249658269
2020	41.08489884685367
2021	51.66766463318942
2022	54.986465727613535