Year	Percent
1960	0.77305
1961	0.86987
1962	0.67757
1963	0.78296
1964	1.00612
1965	0.75299
1966	0.46626
1967	0.41778
1968	0.13793
1969	0.13727
1970	0.36714
1971	0.05326
1972	-0.26293
1973	0.28777
1974	-0.05256
1975	0.94605
1976	-0.08687
1977	-1.10707
1978	-1.07639
1979	-0.85656
1980	-0.4561
1981	-0.38992
1982	-0.59713
1983	-1.41946
1984	-2.54224
1985	-2.6231
1986	-2.87282
1987	-2.97256
1988	-2.08261
1989	-1.53315
1990	-1.30201
1991	-0.46347
1992	-0.53125
1993	-0.94747
1994	-1.26541
1995	-1.17115
1996	-1.1898
1997	-1.18452
1998	-1.79014
1999	-2.65646
2000	-3.65389
2001	-3.471
2002	-3.88489
2003	-4.37555
2004	-5.04418
2005	-5.50787
2006	-5.56404
2007	-4.96312
2008	-4.91261
2009	-2.74251
2010	-3.42585
2011	-3.73758
2012	-3.50141
2013	-2.94764
2014	-2.92357
2015	-2.89195
2016	-2.79868