Year	% of revenue
2010	4.191144125529059
2012	4.12476505777229
2013	4.3320404543244635
2014	4.11351584475481
2015	5.685372304579954
2016	5.50012072521945
2017	6.079156114762082
2018	8.798145618371493
2019	6.535057133221821
2020	8.033924327707703
2021	9.163010885494373