Year	Percent
2006	82.9149
2007	81.3017
2008	84.34919
2009	75.32473
2010	74.74456
2011	78.06487
2012	77.3115
2013	72.44926
2014	70.19095
2015	59.10059
2016	51.99558
2017	55.87348