Year	Percent
1961	49.21514
1962	49.39982
1963	49.39982
1964	49.21514
1965	46.8144
1966	47.73777
1967	47.73777
1968	47.73777
1969	47.73777
1970	46.8144
1971	46.8144
1972	46.8144
1973	46.8144
1974	46.8144
1975	46.8144
1976	46.8144
1977	46.8144
1978	46.8144
1979	45.89104
1980	45.89104
1981	45.89104
1982	44.96768
1983	44.04432
1984	44.04432
1985	44.04432
1986	44.04432
1987	44.04432
1988	44.04432
1989	44.04432
1990	43.95199
1991	43.95199
1992	43.95199
1993	46.44506
1994	46.16805
1995	45.89104
1996	45.61404
1997	45.15235
1998	44.69067
1999	44.506
2000	44.22899
2001	44.22899
2002	43.76731
2003	43.76731
2004	43.58264
2005	43.12096
2006	43.12096
2007	42.84395
2008	41.45891
2009	41.1819
2010	38.9012
2011	38.82733
2012	38.7627
2013	38.67036
2014	38.58726
2015	38.50416
2016	38.50416
2017	38.50416
2018	38.50416
2019	38.50416
2020	38.50416
2021	38.50416