Year	Percent
1961	0.68774
1962	0.68774
1963	0.68774
1964	0.68774
1965	0.68774
1966	0.68774
1967	0.68774
1968	0.68774
1969	0.68774
1970	0.68774
1971	0.68774
1972	0.68774
1973	0.68774
1974	0.68774
1975	0.68774
1976	0.68774
1977	0.68774
1978	0.68774
1979	0.68774
1980	0.68774
1981	0.68774
1982	0.68774
1983	0.68774
1984	0.68774
1985	0.68862
1986	0.68949
1987	0.69037
1988	0.69125
1989	0.69213
1990	0.69301
1991	0.69388
1992	0.69476
1993	0.69564
1994	0.69652
1995	0.6974
1996	0.69827
1997	0.58204
1998	0.58278
1999	0.58351
2000	0.58424
2001	0.58497
2002	0.5857
2003	0.58643
2004	0.58716
2005	0.58789
2006	0.58862
2007	0.58935
2008	0.59008
2009	0.59081
2010	0.59155
2011	0.59228
2012	0.59301
2013	0.5922
2014	0.59223
2015	0.59228
2016	0.5923
2017	0.5923
2018	0.5923
2019	0.5923
2020	0.5923
2021	0.5923