Year	Percent
1960	0.62315
1961	0.76211
1962	0.72684
1963	0.69494
1964	0.66592
1965	0.63931
1966	0.60465
1967	0.60102
1968	0.57452
1969	0.52566
1970	0.54558
1971	0.54262
1972	0.49483
1973	0.47006
1974	0.4234
1975	0.37732
1976	0.35383
1977	0.04414
1978	0.52817
1979	0.3287
1980	0.37122
1981	0.43497
1982	0.58423
1983	0.51646
1984	0.44973
1985	0.44771
1986	0.44572
1987	0.38047
1988	0.35801
1989	0.21
1990	0.27234
1991	-5.81434
1992	-0.89087
1993	3.7326
1994	0.21529
1995	0.40777
1996	-3.82017
1997	1.72076
1998	-1.56512
1999	1.17064
2000	-2.85097
2001	0.31581
2002	0
2003	0
2004	-0.02253
2005	0.06756
2006	-0.04503
2007	-0.09013
2008	-0.03364
2009	-0.12252
2010	-0.25539
2012	-0.30566
2013	-0.27851
2014	-0.40734
2015	-0.8241
2016	-0.69838
2017	-1.17227