Year	Percent
1975	0.77422
1976	0.83343
1977	0.3703
1978	0.60982
1979	-0.76035
1980	1.42102
1981	-0.60125
1982	0.49899
1983	1.15076
1984	0.43588
1985	0.32564
1986	1.38389
1987	3.4657
1988	2.30351
1989	4.08826
1990	1.29807
1991	-1.69359
1992	6.09654
1993	2.67075
1994	-6.11379
1995	-3.75833
1996	5.52517
1997	-3.19288
1998	-7.19711
1999	0.07634
2000	-0.80393
2001	-5.48486
2002	-0.20103
2003	-10.35987
2004	4.34264
2005	6.36375
2006	8.08516
2007	8.53462
2008	6.16745
2009	8.10371
2010	5.10301
2011	6.99416
2012	3.87276
2013	9.55897
2014	8.05989
2015	4.74797
2016	5.77269
2017	5.85898