Year	Percent
1977	-7.82241
1978	-6.45782
1979	-16.22837
1980	-24.14578
1981	-34.07415
1982	-32.44988
1983	-24.86866
1984	-20.1812
1985	-19.6305
1986	-15.94893
1987	-16.42477
1988	-14.25963
1989	-16.19597
1990	-16.43567
1991	-17.14681
1992	-12.59324
1993	-15.78137
1994	-10.8111
1995	-13.27033
1996	-17.03206
1997	-18.77961
1998	-19.6156
1999	-10.0121
2000	-14.30861
2001	-15.96206
2002	-18.41182
2003	-22.32197
2004	-20.26044
2005	-35.56215
2006	-34.36223
2007	-29.89907
2008	-29.53255
2009	-22.52655
2010	-25.39597
2011	-25.59737
2012	-23.65265
2013	-24.92665
2014	1.24864
2015	1.2898
2016	3.7414