Year	Percent
1961	16.12903
1962	16.12903
1963	16.12903
1964	16.12903
1965	16.12903
1966	16.12903
1967	16.12903
1968	16.12903
1969	16.12903
1970	16.12903
1971	16.12903
1972	16.12903
1973	16.12903
1974	16.12903
1975	16.12903
1976	16.12903
1977	16.12903
1978	16.12903
1979	16.12903
1980	16.12903
1981	16.12903
1982	16.12903
1983	16.12903
1984	16.12903
1985	16.12903
1986	16.12903
1987	16.12903
1988	16.62531
1989	16.62531
1990	16.87345
1991	16.87345
1992	17.12159
1993	17.12159
1994	17.12159
1995	17.36973
1996	17.36973
1997	17.866
1998	17.866
1999	17.866
2000	17.866
2001	18.36228
2002	18.61042
2003	18.61042
2004	18.85856
2005	18.85856
2006	18.85856
2007	18.85856
2008	19.35484
2009	19.35484
2010	19.35484
2011	19.60298
2012	19.60298
2013	19.60298
2014	19.60298
2015	19.60298
2016	19.60298
2017	19.60298
2018	19.60298
2019	19.60298
2020	19.60298
2021	19.60298