Year	Percent
1960	1.83287
1961	-1.01553
1962	0.82046
1963	2.45765
1964	2.32068
1965	2.38137
1966	2.78733
1967	2.5707
1968	2.6109
1969	2.74
1970	2.76168
1971	2.74692
1972	2.45736
1973	2.2834
1974	2.06596
1975	1.76639
1976	1.54734
1977	1.36278
1978	1.33818
1979	1.33393
1980	1.25422
1981	1.28095
1982	1.47267
1983	1.44495
1984	1.31207
1985	1.3617
1986	1.4874
1987	1.60361
1988	1.61007
1989	1.53317
1990	1.4673
1991	1.36443
1992	1.22554
1993	1.14962
1994	1.13026
1995	1.08651
1996	1.04814
1997	1.02345
1998	0.95955
1999	0.86585
2000	0.78796
2001	0.72638
2002	0.67
2003	0.62286
2004	0.59393
2005	0.58812
2006	0.55837
2007	0.52227
2008	0.51239
2009	0.49738
2010	0.48296
2011	0.47915
2012	0.48723
2013	0.49371
2014	0.50631
2015	0.50814
2016	0.54148
2017	0.55912