Year	Percent
1960	56.95682
1961	52.9818
1962	44.8833
1963	46.13342
1964	53.51902
1965	57.65517
1966	60.15947
1967	59.79309
1968	55.1469
1969	55.43522
1970	57.00149
1971	54.68888
1972	58.76856
1973	68.88958
1974	66.41877
1975	74.90526
1976	91.00431
1977	78.76767
1978	63.09852
1979	69.22555
1980	93.64058
1981	92.31059
1982	70.08299
1983	64.57766
1984	51.35899
1985	61.88205
1986	53.21198
1987	90.76258
1988	67.93137
1989	73.53341
1990	79.85956
1991	128.03363
1992	152.80573
1993	137.22586
1994	117.93001
1995	112.1166
1996	108.71622
1997	109.4766
1998	107.91042
1999	104.55084
2000	110.68863
2001	111.41877
2002	105.46049
2003	99.79089
2004	105.65746
2005	119.20652
2006	77.67005
2007	77.91487
2008	85.79712
2009	73.87103
2010	79.10717
2011	85.46505
2012	88.17212
2013	78.51822
2014	72.06493
2015	60.02156
2016	54.48307
2017	57.13303