Year	Percent
1961	6.34825
1962	6.4693
1963	6.58411
1964	6.70232
1965	6.81712
1966	6.93534
1967	7.05014
1968	7.16949
1969	7.286
1970	7.4025
1971	7.52185
1972	7.63722
1973	7.75487
1974	7.87024
1975	7.98788
1976	8.10325
1977	8.2209
1978	8.33911
1979	8.45391
1980	8.57042
1981	8.6301
1982	8.69091
1983	8.75513
1984	8.76081
1985	8.76763
1986	8.77218
1987	8.77502
1988	8.77502
1989	8.77786
1990	8.78355
1991	8.78639
1992	8.78923
1993	8.78923
1994	8.79491
1995	8.81765
1996	8.90346
1997	8.90346
1998	8.7807
1999	8.7807
2000	8.7807
2001	8.7807
2002	8.7807
2003	8.7807
2004	8.74376
2005	8.74376
2006	8.74376
2007	8.74376
2008	8.74376
2009	8.74376
2010	8.72444
2011	8.72444
2012	8.72671
2013	8.72671
2014	8.72387
2015	8.72387
2016	8.72387
2017	8.72387
2018	8.72387
2019	8.72387
2020	8.72387
2021	8.72387