Year	% of revenue
1990	8.602796362772896
1991	11.094492868462758
1992	9.419888907252647
1993	7.196341763928403
1994	8.341717735296807
1995	11.281681462631553
1996	13.040354347348313
1997	14.390266559878684
1998	16.147379734800126
1999	20.643527468986626
2000	23.86922887924295
2001	27.471859577468212
2002	47.91003067136204
2003	34.58019866880256
2004	26.457051959090627
2014	8.531905560243922
2015	8.323152110407566
2016	13.956514918176225
2017	11.80666205224561
2018	16.477428949168445
2019	18.555467165529315
2020	11.083173866484053
2021	7.8366139597987745
2022	9.472593793301549