Year	Percent
1960	2.98798
1961	2.70974
1962	2.64254
1963	2.58597
1964	2.51539
1965	2.40983
1966	2.2269
1967	2.05485
1968	1.97171
1969	1.98698
1970	1.97916
1971	2.01089
1972	1.97179
1973	1.83038
1974	1.80905
1975	1.672
1976	1.64637
1977	1.59651
1978	1.49235
1979	1.52357
1980	1.49457
1981	1.46403
1982	1.48808
1983	1.51622
1984	1.48534
1985	1.50417
1986	1.50994
1987	1.44346
1988	1.60427
1989	0.38755
1990	-0.46036
1991	0.26828
1992	0.33558
1993	0.32955
1994	-1.45587
1995	-3.10261
1996	-2.97064
1997	-2.29628
1998	-1.43318
1999	-1.2333
2000	-1.22784
2001	-1.18161
2002	-0.5905
2003	-0.55457
2004	-0.57882
2005	-0.57952
2006	-0.57783
2007	-0.59998
2008	-0.57473
2009	-0.5982
2010	-0.62014
2011	-0.61847
2012	-0.61434
2013	-0.61313
2014	-0.63455
2015	0.39946
2016	0.73402
2017	0.61975