Year	Percent
1960	-5.74668
1961	-5.54678
1962	-6.93057
1963	-7.49473
1964	-7.84892
1965	-9.23564
1966	-6.34366
1967	-3.6244
1968	-6.81165
1969	-9.22861
1970	-8.23258
1971	-7.54656
1972	-5.7504
1973	-7.18824
1974	-14.44423
1975	-6.59484
1976	-8.40825
1977	-9.55476
1978	-10.29876
1979	-16.25763
1980	-13.56245
1981	-14.20721
1982	-7.88708
1983	-3.82338
1984	-1.68299
1985	0.31399
1986	1.07152
1987	4.1305
1988	5.95929
1989	5.38472
1990	4.37779
1991	4.71783
1992	7.25681
1993	10.11916
1994	9.41991
1995	10.92378
1996	10.93295
1997	11.9845
1998	10.88985
1999	13.07151
2000	13.83985
2001	15.62153
2002	17.18441
2003	15.15219
2004	14.37585
2005	10.8884
2006	8.04558
2007	8.27117
2008	8.60449
2009	13.4758
2010	16.63166
2011	18.7045
2012	17.17122
2013	18.78531
2014	17.78718
2015	33.09841
2016	22.00669
2017	32.13421