Year	Percent
1961	50.3634
1962	49.85366
1963	49.28399
1964	48.70738
1965	48.15306
1966	47.84904
1967	47.39411
1968	47.22311
1969	46.54601
1970	46.54638
1971	46.54638
1972	46.54638
1973	46.54638
1974	46.54638
1975	46.54638
1976	46.54638
1977	46.54638
1978	46.54638
1979	46.54638
1980	46.54638
1981	46.54638
1982	46.54674
1983	46.54711
1984	46.54674
1985	46.54674
1986	46.54674
1987	46.54674
1988	46.54528
1989	46.57817
1990	46.61288
1991	46.64759
1992	46.68231
1993	46.71702
1994	46.75283
1995	46.78827
1996	46.82372
1997	46.8577
1998	46.89241
1999	46.92238
2000	46.95819
2001	46.99327
2002	47.03127
2003	47.17498
2004	47.3187
2005	47.47374
2006	47.55339
2007	47.49109
2008	46.42356
2009	45.43021
2010	46.13891
2011	45.79196
2012	45.5813
2013	44.92193
2014	44.28302
2015	44.11877
2016	43.4795
2017	42.98638
2018	42.37154
2019	42.59078
2020	43.02927
2021	43.10235