Year	% of revenue
2008	7.929178929237185
2009	8.899404436249743
2010	9.157122840135647
2011	8.991900268096117
2012	11.023859559306132
2013	10.299995291085235
2014	10.85730226980314
2015	10.199725538148563
2016	9.726458943589218
2017	8.961512821646567
2018	10.488234190821082
2019	10.90270577763879
2020	8.386904657639825