Year	Percent
1967	-12.54207
1968	-7.87255
1969	-7.80859
1970	-5.73197
1971	-6.79985
1972	-9.54004
1973	-12.65531
1974	-28.14642
1975	-19.60322
1976	-10.02544
1977	-6.82372
1978	-18.23058
1979	-15.23362
1980	-14.41687
1981	-15.5031
1982	-15.3783
1983	-16.15662
1984	-17.8146
1985	-25.70164
1986	-20.46693
1987	-14.93306
1988	-17.66549
1989	-13.19504
1990	-15.27698
1991	-15.04444
1992	-18.2438
1993	-14.53859
1994	-17.54872
1995	-17.12209
1996	-14.75147
1997	-9.3843
1998	-7.67044
1999	-9.52446
2000	-10.46539
2001	-7.57593
2002	-1.65438
2003	-7.08946
2004	-7.95725
2005	-8.14759
2006	-4.11878
2007	-8.34552
2008	-13.25244
2009	-7.09948
2010	-12.31096
2011	-8.4612
2012	-4.88549
2013	-14.98548
2014	-15.47845
2015	-15.55098
2016	-16.58258
2017	-18.97323