Year	% of revenue
2013	8.795481209831207
2014	9.031318998127125
2015	10.857599506597184
2016	9.172462708481019
2017	8.918619517994419
2018	7.824305850549443
2019	7.518938530854682
2020	6.875739091374767
2021	7.04482303475686
2022	6.403201064670505