Year	Percent
1960	-2.01136
1961	-2.34538
1962	-3.88547
1963	-0.38832
1964	-2.77585
1965	-2.24302
1966	-2.23126
1967	-2.66588
1968	-2.03357
1969	-2.84285
1970	-2.83291
1971	-2.0256
1972	-0.40818
1973	-1.89398
1974	-3.34864
1975	-0.95969
1976	-4.53164
1977	-3.5675
1978	-2.21643
1979	-2.3817
1980	-0.45027
1981	1.40682
1982	0.90865
1983	2.20953
1984	1.67677
1985	0.7749
1986	-0.19912
1987	2.05471
1988	3.47615
1989	3.79502
1990	5.55615
1991	6.21851
1992	6.90683
1993	7.52747
1994	5.92327
1995	4.70939
1996	5.66348
1997	4.35728
1998	3.07398
1999	5.99966
2000	6.71062
2001	7.14044
2002	6.85202
2003	6.79512
2004	5.64913
2005	5.50447
2006	4.09336
2007	2.89727
2008	3.5234
2009	4.49707
2010	6.94589
2011	6.3945
2012	6.01999
2013	6.60748
2014	6.96232
2015	7.29221
2016	6.19406
2017	7.0582