Year	Percent
1961	69.149
1962	69.149
1963	69.149
1964	69.149
1965	69.149
1966	69.149
1967	69.149
1968	69.149
1969	69.149
1970	69.149
1971	69.149
1972	69.149
1973	69.149
1974	69.149
1975	69.149
1976	69.149
1977	69.149
1978	69.149
1979	69.149
1980	69.149
1981	69.149
1982	69.149
1983	69.149
1984	69.149
1985	69.149
1986	69.149
1987	69.149
1988	69.149
1989	69.149
1990	69.149
1991	69.149
1992	69.149
1993	69.149
1994	69.149
1995	69.14327
1996	69.12679
1997	69.12679
1998	69.12106
1999	69.12106
2000	69.12106
2001	69.12106
2002	69.15401
2003	69.15401
2004	69.15401
2005	69.15401
2006	69.15401
2007	69.15401
2008	69.15401
2009	69.0616
2010	69.05086
2011	69.05659
2012	69.05659
2013	69.05659
2014	69.06734
2015	69.06734
2016	69.01862
2017	69.01862
2018	69.00788
2019	69.00788
2020	70.32943
2021	70.12409