Year	Percent
1960	-10.97744
1961	-10.36109
1962	-10.17398
1963	-10.08952
1964	-8.7196
1965	-6.72402
1966	-6.59676
1967	-8.9988
1968	-9.08265
1969	-10.71518
1970	-10.68653
1971	-14.41962
1972	-14.88927
1973	-16.60774
1974	-16.15215
1975	-22.80286
1976	-18.80299
1977	-22.483
1978	-20.28241
1979	-21.03631
1980	-22.31199
1981	-22.1587
1982	-23.42832
1983	-21.69
1984	-17.79688
1985	-21.10462
1986	-19.9806
1987	-16.72231
1988	-16.13228
1989	-14.89703
1990	-13.48927
1991	-12.90114
1992	-10.68106
1993	-11.722
1994	-10.82598
1995	-12.46636
1996	-17.05309
1997	-15.79136
1998	-15.32358
1999	-14.64959
2000	-15.44718
2001	-13.88242
2002	-12.51954
2003	-13.31209
2004	-14.4717
2005	-16.04773
2006	-13.80752
2007	-14.32513
2008	-16.37594
2009	-15.02216
2010	-10.41335
2011	-8.14662
2012	-11.64201
2013	-14.93566
2014	-9.00562
2015	-10.24045
2016	-4.92763
2017	-5.93929