Year	% of total
2006	27.72077380952381
2007	25.881013693419554
2008	20.02389094449854
2009	21.587544083280218
2010	20.559091298756965
2011	18.30974020862035
2012	19.581537953795376
2013	17.81454821235103
2014	21.23299070247934
2015	18.81408104517272
2016	19.23906141868512