Year	Percent
1975	-1.66865
1976	2.36315
1977	1.17743
1978	2.03624
1979	-0.86113
1980	-3.15563
1981	-6.48019
1982	-5.29413
1983	-3.03101
1984	-0.24386
1985	0.19787
1986	2.52847
1987	2.74082
1988	3.38034
1989	1.62202
1990	0.07444
1991	-3.28461
1992	-9.25797
1993	-1.72783
1994	-1.91955
1995	-2.68411
1996	0.19053
1997	-7.01452
1998	-1.72787
1999	3.8945
2000	2.2521
2001	2.01995
2002	-3.13775
2003	-5.65787
2004	-7.10001
2005	-8.94641
2006	-10.90831
2007	-8.60216
2008	-26.58794
2009	-25.58775
2010	-28.30861
2011	-23.1545
2012	-28.64317
2013	-18.13869
2014	-15.71724
2015	-22.56345
2016	-14.01067
2017	-13.27278