Year	Percent
1961	51.41953
1962	51.41953
1963	51.41953
1964	51.41953
1965	51.41953
1966	51.41953
1967	51.41953
1968	51.41953
1969	51.41953
1970	51.41953
1971	51.41953
1972	51.41953
1973	51.41953
1974	51.41953
1975	51.85901
1976	51.85901
1977	51.85901
1978	52.2985
1979	52.2985
1980	52.2985
1981	52.2985
1982	53.1423
1983	53.10715
1984	53.95095
1985	54.35528
1986	54.32012
1987	54.72444
1988	55.12877
1989	55.09361
1990	55.49793
1991	55.90226
1992	55.90226
1993	56.25385
1994	56.69333
1995	57.57229
1996	58.45126
1997	59.69366
1998	57.06782
1999	57.39453
2000	56.10231
2001	56.68467
2002	57.35466
2003	55.33589
2004	52.16478
2005	53.26351
2006	52.93044
2007	54.81345
2008	52.7589
2009	54.10242
2010	54.49784
2011	54.09091
2012	54.27766
2013	54.77312
2014	54.38452
2015	54.5641
2016	54.31108
2017	53.10699
2018	53.69404
2019	54.84739
2020	55.39302
2021	55.39302