Year	Percent
2004	41.18195
2005	41.33473
2006	41.81567
2007	42.85597
2008	42.81662
2009	44.33004
2010	44.07375
2011	44.1648
2012	45.30656
2013	46.69666
2014	47.83712
2015	50.23564
2016	51.55628
2017	51.62862