Year	% of revenue
1990	34.72029986308646
1991	30.503302442271263
1992	30.288815958324005
1993	24.300272020546526
2001	31.641664906423145
2002	34.803360221966585
2003	19.259621623054336
2004	15.267087381211688
2005	14.024313945065023
2006	16.568083122621385
2007	17.641025744697245
2008	21.20923126515928
2009	15.892665528401182
2010	17.299901509336397
2011	16.62597066872746
2012	12.65490339130356
2013	12.635360649589767
2014	13.226682886883435
2015	11.749169610709584
2016	13.620957695669231
2017	13.81717729594995
2018	12.809689459966803
2019	10.134982977796405
2020	9.999972093575865
2021	9.90755258243877
2022	10.189443149636125