Year	Percent
1965	67.69025
1966	65.69087
1967	59.51835
1968	61.7245
1969	63.49848
1970	59.81682
1971	66.34825
1972	68.59973
1973	71.93442
1974	84.95935
1975	80.47032
1976	77.93317
1977	72.02626
1978	70.53913
1979	77.97012
1980	78.34905
1981	69.49812
1982	54.50477
1983	59.12937
1984	60.11298
1985	53.67492
1986	46.18658
1987	52.54013
1988	47.56461
1989	52.40169
1990	44.93895
1991	16.90204
1992	40.47027
1993	47.77119
1994	50.85366
1995	52.35396
1996	52.28384
1997	52.85396
1998	43.85932
1999	45.9369
2000	56.47364
2001	51.30362
2002	44.61605
2003	52.09224
2004	56.91614
2005	63.9766
2006	65.54462
2007	63.41426
2008	66.75921
2009	59.46913
2010	66.67352
2011	73.21766
2012	74.73185
2013	70.86153
2014	68.50614
2015	53.76538
2016	48.23229