Year	Percent
1995	33.14512
1996	37.50469
1997	38.32534
1998	44.86429
1999	49.49957
2000	45.34315
2001	45.92419
2002	47.93598
2003	48.51155
2004	49.88104
2005	50.41173
2006	52.6486
2007	55.97405
2008	56.43039
2009	60.04977
2010	56.31695
2011	55.31909
2012	56.4626
2013	54.55909
2014	54.49223
2015	56.94565
2016	56.13203
2017	55.35988