Year	% of revenue
2006	22.193294766914004
2007	18.369123847857896
2008	21.189486684359032
2009	35.731285550802546
2010	25.305480467925683
2011	22.009376338808856
2012	27.095092404909348
2013	30.52203793036769
2014	29.824196873941567
2015	37.40664467980241
2016	27.881892362776306
2017	21.502630733263643
2018	21.908950259568865
2019	39.99236967546015
2020	42.62783260436948
2021	26.015515510790145
2022	19.75360190527772