Year	% of revenue
2012	11.390438834956178
2013	10.416318062415861
2014	10.341431428840037
2015	10.573941849492368
2016	9.738828866194421
2017	9.814379024816283
2018	10.442596403118456
2019	10.006684500616231
2020	9.441511638715411
2021	9.866447670259372