Year	Percent
1960	0.89906
1961	1.20872
1962	1.07072
1963	1.00269
1964	1.05091
1965	1.00204
1966	1.02179
1967	1.08486
1968	1.08904
1969	1.11518
1970	1.08259
1971	0.99401
1972	0.99932
1973	1.01372
1974	1.13141
1975	1.26689
1976	1.22122
1977	1.12639
1978	0.99924
1979	0.82924
1980	0.53041
1981	0.28836
1982	0.22183
1983	0.12976
1984	0.07912
1985	0.09506
1986	0.10402
1987	0.10605
1988	0.11983
1989	-0.81814
1990	-0.99058
1991	-0.19571
1992	-0.23105
1993	-0.30634
1994	-0.32955
1995	-0.33226
1996	-0.36519
1997	-0.39679
1998	-0.42838
1999	-0.47935
2000	-0.45624
2001	-0.08238
2002	0.34878
2003	0.33851
2004	0.39812
2005	0.51033
2006	0.63972
2007	0.62831
2008	0.59617
2009	0.60314
2010	0.43061
2011	0.3632
2012	-0.05612
2013	0.11853
2014	0.12154
2015	0.15014
2016	0.09984
2017	0.06328