Year	Percent
1960	0.4722
1961	-1.43247
1962	-2.28697
1963	1.66342
1964	-0.30622
1965	0.42446
1966	2.14647
1967	-0.64004
1968	-2.58756
1969	-3.04882
1970	0.53156
1971	0.03988
1972	0.21116
1973	4.87794
1974	-2.3315
1975	-6.09171
1976	-5.92166
1977	-3.06701
1978	-4.26968
1979	-5.0759
1980	-4.89848
1981	-3.33776
1982	-5.80149
1983	-6.74141
1984	-1.04904
1985	2.12211
1986	3.95377
1987	0.42079
1988	1.45374
1989	-2.15648
1990	-5.76781
1991	-2.99044
1992	-4.89842
1993	-8.44725
1994	-6.30817
1995	-7.82397
1996	-8.78664
1997	-10.33735
1998	-9.13379
1999	-3.93084
2000	-1.99127
2001	-6.85524
2002	-8.94107
2003	-7.53522
2004	-5.49722
2005	-5.60458
2006	-1.78471
2007	-0.09781
2008	-2.45819
2009	-1.12568
2010	-1.81291
2011	-3.63623
2012	-3.26135
2013	-4.20994
2014	-3.64618
2015	-5.89857
2016	-8.96925
2017	-9.55498