Year	% of revenue
2007	9.839912209709778
2008	10.44863183298216
2009	9.496262218691365
2010	9.32486204964738
2011	8.750397856299674
2012	7.595785662989815
2013	13.943297863249596
2014	14.074965461757962
2015	13.594692963891358
2016	14.145949024622723
2017	15.39998160476813
2018	15.170017718117265
2019	15.217885077919993
2020	14.280467221709362
2021	14.280467221709362
2022	17.604908727947745