Year	Percent
1960	-0.30493
1961	-1.58411
1962	-3.66422
1963	-1.01112
1964	-4.83198
1965	-4.53072
1966	-3.63304
1967	-5.94528
1968	-6.33513
1969	-7.11538
1970	-7.32831
1971	-3.23322
1972	-6.2809
1973	-8.22025
1974	-16.70242
1975	-11.74712
1976	-12.07417
1977	-9.68693
1978	-5.29805
1979	-8.33005
1980	-13.54185
1981	-12.04567
1982	-15.12696
1983	-6.08942
1984	-4.06506
1985	-12.15473
1986	-0.69145
1987	-4.37867
1988	-5.28868
1989	-6.69861
1990	-6.79092
1991	-4.677
1992	-1.08162
1993	-2.45526
1994	-10.34773
1995	-7.11515
1996	-7.31672
1997	-7.81688
1998	-8.5378
1999	-7.33261
2000	-7.89269
2001	-7.68836
2002	-10.57767
2003	-9.58834
2004	-10.54179
2005	-14.20489
2006	-13.09655
2007	-12.49754
2008	-17.95727
2009	-26.53494
2010	-26.89368
2011	-26.88447
2012	-17.5027
2013	-16.44525
2014	-18.25635
2015	-22.47171
2016	-17.03591
2017	-16.33987