Year	Percent
1961	45.13288
1962	45.61333
1963	46.33402
1964	49.41194
1965	49.40193
1966	49.472
1967	49.48701
1968	49.67219
1969	49.79731
1970	49.94745
1971	50.19769
1972	50.54802
1973	50.9484
1974	51.3688
1975	52.08448
1976	52.7401
1977	52.7401
1978	53.10045
1979	53.10045
1980	53.45078
1981	53.85116
1982	54.25154
1983	56.55373
1984	57.55468
1985	58.05515
1986	59.14118
1987	59.14118
1988	59.14118
1989	59.3664
1990	59.86687
1991	60.21721
1992	60.3173
1993	60.46744
1994	60.56754
1995	60.66763
1996	60.91787
1997	60.91787
1998	61.2682
1999	61.3683
2000	62.61949
2001	63.11996
2002	64.12091
2003	65.62234
2004	66.37305
2005	66.37305
2006	67.37776
2007	68.38246
2008	69.63741
2009	70.64211
2010	71.14004
2011	71.63874
2012	71.88809
2013	71.88809
2014	71.88809
2015	71.88809
2016	71.88809
2017	71.88809
2018	71.88809
2019	71.88809
2020	71.88809
2021	71.88809