Year	Percent
1960	77.82349
1961	71.25676
1962	74.67209
1963	87.96828
1964	102.19938
1965	92.21962
1966	80.48907
1967	82.27257
1968	87.61505
1969	88.50844
1970	86.63294
1971	87.45997
1972	80.39968
1973	80.82456
1974	82.7464
1975	68.78969
1976	62.78432
1977	73.74004
1978	73.14208
1979	76.844
1980	85.8164
1981	83.421
1982	74.2034
1983	70.34056
1984	66.38385
1985	65.63209
1986	59.75685
1987	64.43626
1988	80.45212
1989	90.89475
1990	93.56595
1991	79.63326
1992	70.04817
1993	71.54099
1994	77.46735
1995	76.68697
1996	81.48345
1997	75.7714
1998	74.48161
1999	77.85102
2000	84.02065
2001	85.71761
2002	76.84412
2003	80.87444
2004	78.42326
2005	76.76126
2006	80.52276
2007	75.04167
2008	90.42358
2009	72.09013
2010	84.3755
2011	86.139
2012	87.44182
2013	93.88032
2014	103.12957
2015	68.22438
2016	69.40849
2017	66.78254