Year	Percent
1990	40.63
1991	40.88
1992	41.13
1993	41.38
1994	41.63
1995	41.88
1996	42.13
1997	42.38
1998	42.63
1999	42.88
2000	43.13
2001	43.13
2002	43.13
2003	43.13
2004	43.13
2005	43.13
2006	43.13
2007	43.13
2008	43.13
2009	43.13
2010	43.13
2011	43.13
2012	43.13
2013	43.13
2014	43.13
2015	43.13