Year	Percent
1961	44.91248
1962	44.91248
1963	45.43188
1964	45.43188
1965	45.95128
1966	45.95128
1967	46.47068
1968	47.35366
1969	46.24214
1970	46.03958
1971	46.46549
1972	46.46549
1973	46.72519
1974	46.98489
1975	46.98489
1976	46.97969
1977	45.9357
1978	45.9305
1979	45.92531
1980	45.92012
1981	45.91492
1982	45.90973
1983	45.90453
1984	45.89934
1985	45.89415
1986	45.88376
1987	45.87337
1988	45.86298
1989	45.8474
1990	46.06555
1991	45.23451
1992	45.60328
1993	45.80065
1994	46.30447
1995	45.78507
1996	46.26292
1997	44.8138
1998	43.57762
1999	47.32769
2000	46.8862
2001	45.70197
2002	45.44746
2003	44.83457
2004	45.12024
2005	45.58251
2006	44.09702
2007	44.16455
2008	48.17431
2009	48.18989
2010	48.18989
2011	46.56417
2012	46.56417
2013	46.57975
2014	46.60053
2015	48.44959
2016	48.24183
2017	48.42362
2018	48.60541
2019	48.79759
2020	48.97938
2021	49.40009