Year	Percent
1960	1.11957
1961	0.92902
1962	0.92003
1963	0.87704
1964	0.9937
1965	1.08584
1966	1.02403
1967	1.23067
1968	1.30766
1969	0.98543
1970	1.11063
1971	1.20508
1972	1.10414
1973	1.10494
1974	1.09261
1975	1.08129
1976	1.05685
1977	1.02913
1978	0.96288
1979	0.88158
1980	0.80296
1981	0.71088
1982	0.60039
1983	0.48718
1984	0.41526
1985	0.36237
1986	0.29878
1987	0.25933
1988	0.21206
1989	0.15678
1990	0.10183
1991	0.25453
1992	0.48976
1993	0.51854
1994	0.4761
1995	0.44137
1996	0.41652
1997	0.41912
1998	0.41385
1999	0.40532
2000	0.44714
2001	0.69407
2002	1.4126
2003	1.80845
2004	1.72547
2005	1.68935
2006	1.69035
2007	1.85108
2008	1.59533
2009	0.88574
2010	0.46041
2011	0.35534
2012	0.06493
2013	-0.32767
2014	-0.29895
2015	-0.07759
2016	0.08443
2017	0.18906