Year	Percent
1962	16.50859
1963	17.35693
1964	18.90911
1965	18.63626
1966	18.35239
1967	20.42784
1968	20.79983
1969	6.71512
1970	19.87853
1971	20.39097
1972	20.83135
1973	18.03674
1974	16.63353
1975	14.98171
1976	13.16856
1977	13.48761
1980	72.43873
1981	60.3263
1982	153.44726
1983	111.67106
1984	88.25652
1985	58.88736
1986	64.27752
1987	79.31454
1988	75.64245
1989	76.20812
1990	117.86104
1991	99.03742
1992	76.01837
1993	78.06388
1994	108.64135
1995	158.50673
1996	219.06944
1997	148.28963
1998	218.98572
1999	154.4679
2000	131.04974
2001	147.87906
2002	55.68633
2003	116.20398
2004	76.99936
2005	39.47675
2006	26.50112
2007	29.58591
2008	27.54175
2009	39.39283
2010	38.0563
2011	32.04927
2012	41.14814
2013	30.30805
2014	28.7093
2015	24.70145
2016	16.56384
2017	12.04754