Year	Percent
1961	29.352
1962	29.352
1963	30.48092
1964	30.48092
1965	30.48092
1966	30.48092
1967	30.48092
1968	30.48092
1969	30.48092
1970	31.60984
1971	32.73877
1972	32.73877
1973	32.73877
1974	32.73877
1975	32.73877
1976	32.73877
1977	32.73877
1978	33.86769
1979	33.86769
1980	33.86769
1981	34.99661
1982	34.99661
1983	34.99661
1984	34.99661
1985	36.12554
1986	36.12554
1987	36.12554
1988	36.12554
1989	36.12554
1990	35.2111
1991	35.63106
1992	36.05102
1993	36.47098
1994	36.89093
1995	37.31089
1996	37.73085
1997	38.04809
1998	38.1576
1999	38.27049
2000	38.38338
2001	38.49627
2002	38.60917
2003	38.68819
2004	39.23809
2005	39.86701
2006	40.49594
2007	41.11357
2008	41.74125
2009	41.98092
2010	42.22059
2011	42.46026
2012	42.3319
2013	42.9396
2014	43.17927
2015	43.41894
2016	43.65861
2017	43.89828
2018	44.13795
2019	44.37762
2020	44.61639
2021	44.61639