Year	Percent
2006	15.21564
2007	16.9086
2008	14.83667
2009	22.85745
2010	23.85198
2011	21.13404
2012	21.92576
2013	26.24312
2014	27.86858
2015	37.75743
2016	44.12695
2017	40.74528