Year	% of revenue
2004	14.524646921711442
2005	16.327526769059915
2006	18.63067623731496
2007	17.514492678614165
2008	16.837101852292356
2009	19.658391410622862
2010	18.618920756746295
2011	19.412405695631946
2012	21.314344550538227
2013	36.27593740123815
2014	33.8641915681785
2015	35.667560320011766
2016	39.84869361067139
2017	36.94685021387634
2018	40.13859153504933
2019	37.39232049785062
2020	36.18382613920422
2021	35.246763764996984
2022	34.679439944189134