Year	% of revenue
2012	3.2755063042677715
2014	3.773311452348127
2015	5.685372304579954
2016	6.443026513019404
2017	6.499309206073938
2018	9.007485428885067
2019	6.461241766163401
2020	8.75740659825619
2021	9.163010885494373