Year	Percent
1960	-13.36831
1961	-15.30918
1962	-16.91295
1963	-18.35091
1964	-19.76569
1965	-18.90244
1966	-21.68022
1967	-26.15965
1968	-39.89474
1969	-29.79298
1970	-36.25816
1971	-28.4141
1972	-23.17073
1973	-23.13367
1974	-23.85189
1975	-20.19798
1976	-15.93509
1977	-18.40894
1978	-16.46385
1979	-11.12691
1980	-13.38306
1981	-21.82526
1982	-14.71221
1983	-0.48217
1984	2.84907
1985	15.05929
1986	19.20211
1987	26.68738
1988	26.59229
1989	13.08833
1990	5.26349
1991	6.50064
1992	6.60787
1993	7.98339
1994	7.46419
1995	7.07782
1996	16.70131
1997	13.15706
1998	-3.2627
1999	11.46546
2000	11.73889
2001	9.79015
2002	12.47908
2003	11.81967
2004	8.22975
2005	17.34176
2006	18.17436
2007	13.92753
2008	-5.36798
2009	-17.08412
2010	-7.62887
2011	-3.5676
2012	-11.93338
2013	0.0759
2014	6.88772
2015	-1.32338
2016	13.08985