Year	% of revenue
1998	20.278548021174693
1999	15.574007442260971
2000	31.014307821790243
2001	24.081774081774082
2002	18.735627196598255
2003	12.500000000000005
2004	15.981552035291758
2005	9.706554463346512
2006	14.08315883936584
2007	17.877151621162575
2008	20.877038641131488
2009	16.967441362321946
2010	17.28473271283076
2011	26.16173544206094
2012	18.460429890683688
2013	15.382350632016959
2014	15.641988311022425
2015	15.761828952572326
2016	16.79272127077783
2017	19.57546598427315
2018	18.995705818313777
2019	16.017970797454137
2020	16.992835505120933
2021	24.11941755470593