Year	Percent
1965	74.7917
1966	74.86692
1967	65.85109
1968	65.28338
1969	65.79066
1970	61.61892
1971	61.17859
1972	59.55947
1973	61.02459
1974	59.13528
1975	49.21357
1976	49.2161
1977	46.46098
1978	42.41826
1979	49.03816
1980	45.84684
1981	40.73712
1982	39.78375
1983	38.20267
1984	40.83753
1985	41.83584
1986	37.52635
1987	37.70911
1988	39.22077
1989	40.30891
1990	32.54599
1991	32.13271
1992	33.23762
1993	33.73489
1994	49.75875
1995	44.00045
1996	47.18929
1997	45.96095
1998	45.51746
1999	31.54375
2000	31.18321
2001	31.79212
2002	30.19299
2003	33.03357
2004	33.89314
2005	33.77354
2006	30.02396
2007	26.06661
2008	24.77837
2009	25.3553
2010	24.31234
2011	23.83487
2012	24.76284
2013	24.91754
2014	24.68564
2015	23.97832
2016	25.15014
2017	26.34544
2018	24.62747
2019	23.56832
2020	26.66211
2021	24.09631
2022	24.89705