Year	Percent
1960	0.78267
1961	0.76985
1962	0.87943
1963	0.92588
1964	0.80514
1965	0.85319
1966	0.83456
1967	0.45721
1968	0.44472
1969	0.79298
1970	0.33266
1971	0.18348
1972	0.47848
1973	0.31494
1974	0.03897
1975	-0.37285
1976	-0.42877
1977	-0.22638
1978	-0.08703
1979	0.04421
1980	0.20743
1981	0.15231
1982	-0.09511
1983	-0.26215
1984	-0.34567
1985	-0.22349
1986	0.04577
1987	0.15362
1988	0.39068
1989	0.77334
1990	0.86197
1991	0.72861
1992	0.76035
1993	0.65739
1994	0.34686
1995	0.2939
1996	0.28947
1997	0.14631
1998	0.01514
1999	0.06463
2000	0.13543
2001	0.16823
2002	0.16813
2003	0.05536
2004	-0.02171
2005	-0.05678
2006	-0.1128
2007	-0.13372
2008	-0.19014
2009	-0.25338
2010	-0.1532
2011	-1.85371
2012	0.18773
2013	0.2729
2014	0.41688
2015	0.8657
2016	0.80722
2017	0.41968