Year	Percent
1970	0.60906
1971	0.65494
1972	0.70591
1973	0.68987
1974	0.70257
1975	0.65953
1976	-0.4269
1977	0.15226
1978	0.14821
1979	0.31818
1980	0.14638
1981	0.16073
1982	0.22156
1983	0.09915
1984	-0.02598
1985	0.17732
1986	0.18536
1987	0.07738
1988	0.43559
1989	0.96928
1990	0.81893
1991	1.11511
1992	0.66532
1993	1.1961
1994	3.20575
1995	2.23744
1996	0.41221
1997	1.60868
1998	3.77117
1999	9.46697
2000	21.93809
2001	5.63525
2002	2.48031
2003	0.54326
2004	-3.50243
2005	4.8577
2006	0.84319
2007	3.69711
2008	0.62011
2009	1.1739
2010	-3.65467
2011	3.9415
2012	-4.99767
2013	0.19801
2014	1.86331
2015	0.61426
2016	2.77911
2017	-0.69762