Year	Percent
1961	8.61362
1962	8.61362
1963	8.61362
1964	8.61362
1965	9.26989
1966	9.26989
1967	9.26989
1968	9.26989
1969	9.26989
1970	9.84413
1971	9.84413
1972	9.84413
1973	9.84413
1974	9.84413
1975	10.33634
1976	10.33634
1977	10.41838
1978	10.41838
1979	10.50041
1980	10.50041
1981	10.74651
1982	10.82855
1983	11.07465
1984	11.07465
1985	11.23872
1986	11.56686
1987	11.73093
1988	12.05906
1989	12.22313
1990	12.46924
1991	12.63331
1992	12.87941
1993	13.04348
1994	13.12551
1995	13.53568
1996	13.69975
1997	13.78179
1998	14.10993
1999	14.19196
2000	14.35603
2001	14.5201
2002	14.60213
2003	14.7662
2004	14.84824
2005	15.01231
2006	15.17637
2007	15.34044
2008	15.34044
2009	15.34044
2010	15.34044
2011	15.34044
2012	15.34044
2013	15.34044
2014	15.34044
2015	15.34044
2016	15.34044
2017	15.34044
2018	15.34044
2019	15.34044
2020	15.34044
2021	15.34044