Year	Percent
1970	-2.02306
1971	-2.51247
1972	1.04659
1973	4.65116
1974	2.02116
1975	0.24946
1976	0.20969
1977	-3.52574
1978	-1.83549
1979	-3.49936
1980	2.27702
1981	6.93999
1982	-1.21292
1983	9.22363
1984	-8.20459
1985	2.43916
1986	-6.7789
1987	-13.22651
1988	-14.72995
1989	-55.2422
1990	-19.77852
1991	4.1267
1992	-13.42066
1993	-10.86769
1994	-4.98768
1995	-2.96843
1996	2.2193
1997	-0.98966
1998	0.96296
1999	-6.94567
2000	-16.58887
2001	-3.51031
2002	-6.82491
2003	-5.98649
2004	-2.51332
2005	1.5554
2006	-6.22149
2007	-8.40084
2008	-6.54973
2009	-2.41007
2010	-5.67027
2011	3.28538
2012	3.40245
2013	3.6295
2014	-1.13867
2015	3.80529
2016	7.3475
2017	4.7752