Year	Percent
1961	36.18731
1962	36.25658
1963	36.35356
1964	36.42283
1965	36.4921
1966	36.56137
1967	36.63065
1968	36.76919
1969	36.83846
1970	36.90773
1971	36.977
1972	37.04627
1973	37.11554
1974	37.18482
1975	37.25409
1976	37.32336
1977	37.39263
1978	37.53117
1979	37.66971
1980	37.73899
1981	37.80826
1982	38.01607
1983	38.08534
1984	38.29316
1985	38.98587
1986	39.05514
1987	39.12441
1988	39.13827
1989	39.13827
1990	39.13827
1991	39.13827
1992	38.99972
1993	38.94431
1994	38.93045
1995	38.93045
1996	38.93045
1997	38.9166
1998	38.9166
1999	38.84733
2000	38.93045
2001	41.58382
2002	44.75035
2003	49.41355
2004	52.26836
2005	52.81269
2006	55.83098
2007	50.20393
2008	51.43017
2009	52.6596
2010	54.45248
2011	55.66126
2012	53.15392
2013	54.7056
2014	54.71045
2015	54.71045
2016	54.71045
2017	54.71045
2018	54.71045
2019	54.71045
2020	54.71045
2021	54.71045