Year	Percent
1967	-8.94114
1968	-5.61169
1969	-5.20091
1970	-6.90116
1971	-5.64763
1972	-5.20818
1973	-2.7768
1974	-7.09675
1975	-11.5388
1976	-8.65241
1977	-9.73618
1978	-9.23844
1979	-12.06466
1980	-11.61263
1981	-10.69515
1982	-11.8189
1983	-11.05906
1984	-11.55575
1985	-12.39083
1986	-10.76586
1987	-7.7688
1988	-8.08376
1989	-7.86385
1990	-7.83288
1991	-1.5608
1992	-3.16926
1993	-6.13439
1994	-2.76202
1995	-2.71281
1996	-4.52392
1997	-4.68836
1998	-1.04214
1999	-1.61296
2000	-1.24696
2001	-1.05245
2002	-0.0904
2003	0.59344
2004	1.03367
2005	-3.8743
2006	-7.4138
2007	-6.5612
2008	-10.82958
2009	-7.28034
2010	-5.83639
2011	-5.00657
2012	-8.01218
2013	-6.77929
2014	-6.41608
2015	-6.44585
2016	-7.01478
2017	-9.31725