Year	Percent
1961	43.5273
1962	43.54129
1963	43.55401
1964	43.56418
1965	43.5769
1966	43.58453
1967	43.61759
1968	43.74475
1969	43.87701
1970	43.9851
1971	43.9851
1972	44.00926
1973	44.07538
1974	44.07538
1975	44.10082
1976	44.10082
1977	44.10082
1978	44.10082
1979	44.10082
1980	44.10082
1981	44.1644
1982	44.26613
1983	44.26613
1984	44.3933
1985	44.45688
1986	44.52046
1987	44.64763
1988	44.71121
1989	44.77479
1990	44.83837
1991	45.11686
1992	45.39536
1993	45.67385
1994	45.95234
1995	46.23083
1996	46.50932
1997	46.78781
1998	47.0663
1999	47.3448
2000	47.62329
2001	47.90507
2002	48.18685
2003	48.46863
2004	48.75041
2005	49.03219
2006	49.31397
2007	49.59575
2008	49.87752
2009	50.1593
2010	50.44108
2011	50.70359
2012	50.96609
2013	51.2286
2014	51.4911
2015	51.75361
2016	52.14999
2017	52.4319
2018	52.66389
2019	52.66389
2020	52.66389
2021	52.66389