Year	Percent
1990	45.94
1991	47.39
1992	48.83
1993	50.28
1994	51.73
1995	53.18
1996	54.63
1997	56.08
1998	57.53
1999	58.98
2000	60.42
2001	60.42
2002	60.42
2003	60.42
2004	60.42
2005	60.42
2006	60.42
2007	60.42
2008	60.42
2009	60.42
2010	60.42
2011	60.42
2012	60.42
2013	60.42
2014	60.42
2015	60.42