Year	% of revenue
2012	44.945001560902746
2013	47.489522863016965
2014	44.125472188393346
2015	47.42497393204437
2016	49.193430293333854
2017	48.96449424212107
2018	47.3532190094245
2019	46.142349334418675
2020	41.10956254390358
2021	40.45992834465748
