Year	% of revenue
2003	34.251352024359164
2004	36.991454310461236
2005	36.661345432730776
2006	35.16868786689833
2007	34.60388457205913
2008	34.993232416973285
2009	32.83422407816422
2010	32.79027007885812
2011	34.39076468997693
2012	34.954887401438704
2013	34.213511907572894
2014	34.07227488905128
2015	35.18985345329743
2016	35.79192223526411
2017	35.293046407578046
2018	36.041711837606954
2019	34.64051253021722
2020	35.931457933281195
2021	36.75166169700279