Year	Percent
1960	-7.72796
1961	-12.707
1962	-16.55304
1963	-4.34503
1964	20.91389
1965	20.5734
1966	21.94456
1967	18.30907
1968	16.05794
1969	15.33431
1970	15.85112
1971	15.61341
1972	-0.98116
1973	0.49331
1974	-10.99249
1975	-21.9574
1976	-39.95011
1977	-40.79373
1978	-31.4789
1979	-26.60197
1980	-29.83327
1981	-29.87887
1982	-44.63865
1983	-30.56569
1984	-27.55046
1985	-20.87908
1986	-23.15974
1987	-17.49534
1988	-12.76013
1989	-6.9081
1990	-15.08977
1991	-6.19805
1992	-0.67151
1993	1.99959
1994	3.25304
1995	6.10395
1996	4.09713
1997	-0.38194
1998	-8.13886
1999	-9.37808
2000	-15.34178
2001	-17.23245
2002	-13.92893
2003	-25.36268
2004	-40.9595
2005	-51.75645
2006	-5.04153
2007	-13.26098
2008	-21.0926
2009	-15.81733
2010	-10.43081
2011	-6.3541
2012	-26.44598
2013	-22.2144
2014	-26.63009
2015	-35.1557
2016	-26.22748
2017	-22.91197