Year	Percent
1960	-16.32302
1961	-15.55734
1962	-13.60856
1963	-15.62729
1964	-8.77067
1965	-13.7889
1966	-15.80645
1967	-10.84954
1968	-15.32061
1969	-16.11738
1970	-14.91119
1971	-12.0224
1972	-14.65438
1973	-9.94505
1974	-10.94258
1975	-16.76421
1976	-8.43137
1977	-4.62912
1978	-17.92182
1979	-17.64025
1980	-13.95881
1981	-5.8298
1982	-6.35035
1983	-7.57133
1984	1.94448
1985	-5.70723
1986	-2.13809
1987	-2.35735
1988	-9.2208
1989	-15.73766
1990	-9.63869
1991	-6.03573
1992	-19.24961
1993	-16.09167
1994	-32.11231
1995	-17.71994
1996	-9.05092
1997	-12.2289
1998	-5.33485
1999	-15.27141
2000	-9.73133
2001	-11.13595
2002	-10.17956
2003	-10.50154
2004	-13.76974
2005	-21.20567
2006	-19.0923
2007	-9.82127
2008	-16.65225
2009	-11.62577
2010	-12.0734
2011	-7.23353
2012	-15.47479
2013	-6.94956
2014	-5.92348
2015	-6.59823
2016	-11.97388
2017	-7.00418