Year	Percent
1970	0.49945
1971	0.64458
1972	0.69706
1973	0.92748
1974	1.2746
1975	0.66816
1976	1.0333
1977	1.85096
1978	1.05284
1979	0.75539
1980	0.09283
1981	1.0564
1982	0.70556
1983	0.53276
1984	-0.29078
1985	-0.65192
1986	1.29283
1987	0.1982
1988	0.27413
1989	1.48035
1990	0.83739
1991	-0.32625
1992	-0.51064
1993	0.8223
1994	2.15241
1995	1.57391
1996	1.94415
1997	2.4084
1998	2.82415
1999	4.17531
2000	4.86357
2001	1.83342
2002	1.54118
2003	1.82703
2004	1.86055
2005	3.25819
2006	3.43864
2007	6.18478
2008	4.44882
2009	2.23364
2010	5.04141
2011	2.06409
2012	5.37128
2013	-0.0477
2014	0.65683
2015	1.76462
2016	-5.02381
2017	0.15388