Year	% of revenue
2005	44.360702311757564
2006	46.65090789599212
2007	51.9486474094452
2008	66.3092335920198
2009	51.802939489228585
2010	44.583556409996085
2011	37.26340402616496
2012	32.76429133919842
2013	40.536712917231185
2014	35.5531470595542
2015	26.37161630337188
2016	26.778613181779708
2017	23.450355283492655
2018	24.363827205597673
2019	20.11072039964929
2020	19.819246613628355
2021	14.567315161104283