Year	Percent
1960	1.36234
1961	1.30133
1962	1.28742
1963	1.24052
1964	1.21434
1965	1.21604
1966	1.16929
1967	1.15577
1968	1.13733
1969	1.16078
1970	1.12443
1971	1.15494
1972	1.18675
1973	1.18518
1974	1.15177
1975	1.0976
1976	1.05941
1977	1.01519
1978	0.98391
1979	0.95112
1980	0.95365
1981	0.92188
1982	0.88412
1983	0.88308
1984	0.93964
1985	0.99455
1986	1.09985
1987	1.17372
1988	1.05828
1989	0.73798
1990	0.2693
1991	-0.28827
1992	-0.75298
1993	-0.98357
1994	-0.83971
1995	-0.45509
1996	0.03909
1997	0.41816
1998	0.70882
1999	0.7635
2000	0.68157
2001	0.5655
2002	0.51
2003	0.42823
2004	0.35166
2005	0.29452
2006	0.20276
2007	0.13425
2008	0.07634
2009	0.06598
2010	0.06799
2011	0.11939
2012	0.11925
2013	0.1663
2014	0.19469
2015	0.25152
2016	0.30994
2017	0.3516