Year	Percent
1970	0.2699
1971	0.23151
1972	0.24785
1973	0.40153
1974	0.27124
1975	0.16575
1976	0.25514
1977	0.24155
1978	0.1993
1979	0.25479
1980	0.30721
1981	0.41515
1982	0.35762
1983	0.29269
1984	0.72633
1985	1.04684
1986	1.87854
1987	2.69756
1988	2.90445
1989	1.01045
1990	0.20367
1991	-0.36024
1992	1.18055
1993	0.81719
1994	0.56729
1995	1.10171
1996	1.25065
1997	1.39958
1998	1.16988
1999	0.08017
2000	0.98667
2001	3.53789
2002	1.76796
2003	3.98843
2004	1.59911
2005	-4.72299
2006	3.23029
2007	1.69265
2008	3.02946
2009	1.2374
2010	1.57906
2011	0.59175
2012	0.37344
2013	-0.04891
2014	0.38668
2015	-0.02216
2016	-0.13722
2017	0.69732