Year	Percent
1970	0.0681
1972	0.02117
1973	0.00728
1974	-0.02524
1975	0.02322
1976	0.08368
1977	0.09501
1978	0.07809
1979	-0.02945
1980	0.11864
1981	0.19298
1982	0.18171
1983	0.07679
1984	0.09356
1985	-0.02451
1986	-0.05181
1987	0.0578
1988	0.01312
1989	0.02282
1990	-0.25087
1991	-0.00545
1992	0.00128
1993	-0.0018
1994	0.7752
1995	0.08677
1996	0.00444
1997	0.83808
1998	3.29502
1999	3.47125
2000	3.19969
2001	4.3541
2002	4.81775
2003	7.64565
2004	7.04216
2005	5.88772
2006	5.14157
2007	3.27759
2008	3.03177
2009	3.24796
2010	3.1443
2011	2.57604
2012	3.39294
2013	2.34214
2014	1.52314
2015	1.77897
2016	1.11291
2017	0.90673