Year	Percent
1961	55.66426
1962	55.65139
1963	55.63852
1964	56.16632
1965	56.15345
1966	56.14058
1967	56.1277
1968	56.11483
1969	57.08033
1970	58.27111
1971	58.3033
1972	58.93409
1973	59.50051
1974	59.80947
1975	60.24717
1976	60.68486
1977	60.97451
1978	60.22786
1979	59.81591
1980	58.32261
1981	58.75386
1982	59.32029
1983	59.99614
1984	60.13131
1985	59.78373
1986	59.17868
1987	59.25592
1988	59.0242
1989	59.3396
1990	59.15937
1991	59.28167
1992	60.21498
1993	60.64624
1994	59.75154
1995	60.16993
1996	60.01545
1997	60.16349
1998	60.63337
1999	61.31565
2000	61.47657
2001	61.14186
2002	62.84114
2003	62.97631
2004	63.2724
2005	63.23378
2006	63.11792
2007	63.11148
2008	63.60067
2009	63.0085
2010	64.61123
2011	64.83007
2012	63.86457
2013	63.99974
2014	62.82827
2015	63.29815
2016	62.45237
2017	62.71177
2018	62.43885
2019	62.43885
2020	62.43885
2021	62.43885