Year	Percent
2006	58.9419
2007	57.4109
2008	55.7412
2009	52.6532
2010	53.8517
2011	55.5484
2012	55.2099
2013	52.508
2014	51.9737
2015	49.7045
2016	47.9334
2017	45.7474