Year	Percent
1961	44.27733
1962	44.28612
1963	44.2949
1964	44.30369
1965	44.31247
1966	44.32126
1967	44.33004
1968	44.33883
1969	44.34761
1970	44.3564
1971	44.36518
1972	44.37397
1973	44.38275
1974	44.39154
1975	44.93095
1976	44.94149
1977	44.945
1978	44.945
1979	44.945
1980	44.945
1981	44.945
1982	44.945
1983	44.945
1984	44.81323
1985	46.30495
1986	46.33834
1987	46.44727
1988	46.84612
1989	47.53312
1990	47.03588
1991	47.22388
1992	47.5665
1993	47.15887
1994	47.84763
1995	47.82303
1996	46.47538
1997	46.72664
1998	46.48768
1999	47.22212
2000	46.86193
2001	47.15711
2002	47.12022
2003	47.21861
2004	47.42594
2005	47.44351
2006	47.53488
2007	47.56299
2008	47.58935
2009	47.94075
2010	47.98468
2011	48.53112
2012	48.55044
2013	48.56977
2014	48.5891
2015	48.61018
2016	48.62951
2017	48.64884
2018	48.66817
2019	48.68749
2020	48.68749
2021	48.68749