Year	Percent
1975	-21.20621
1976	-12.87811
1977	-19.94799
1978	-20.59231
1979	-19.08542
1980	-17.80876
1981	-13.07078
1982	-13.31837
1983	-13.56559
1984	-12.44205
1985	-10.09311
1986	-3.3856
1987	-2.98281
1988	-5.42613
1989	-8.41419
1990	-5.60708
1991	-10.0086
1992	-11.18309
1993	-0.43363
1994	-0.39718
1995	-0.86492
1996	-0.43473
1997	-1.39407
1998	2.48675
1999	2.64238
2000	2.43139
2001	4.56696
2002	1.17024
2003	1.52276
2004	-0.12556
2005	-0.53327
2006	-2.93474
2007	-4.75698
2008	-12.76492
2009	-5.34769
2010	-7.26547
2011	-2.93395
2012	-1.4813
2013	1.8252
2014	2.04818
2015	0.80318
2016	-0.77666
2017	-3.97371