Year	Percent
1990	34.8
1991	34.8
1992	34.8
1993	34.8
1994	34.8
1995	34.8
1996	34.8
1997	34.8
1998	34.8
1999	34.8
2000	34.8
2001	34.64
2002	34.48
2003	34.32
2004	34.16
2005	34
2006	34.24
2007	34.48
2008	34.72
2009	34.96
2010	35.2
2011	35.2
2012	35.2
2013	35.06
2014	35.06
2015	35.06