Year	Percent
1970	0.38214
1971	1.77934
1972	0.7962
1973	2.95147
1974	0.87277
1975	-25.78236
1976	0.29648
1977	0.7628
1978	0.52523
1979	9.81799
1980	3.82123
1981	1.66367
1982	1.99547
1983	0.17356
1984	1.17289
1985	1.02157
1986	0.55932
1987	0.18448
1988	0.20124
1989	0.3533
1990	0.66067
1991	0.15722
1992	0.51553
1993	1.28741
1994	0.15804
1995	0.49385
1996	-0.03019
1997	-0.23752
1998	0.00965
1999	1.07561
2000	3.09944
2001	5.92031
2002	5.08449
2003	6.52291
2004	22.04059
2005	37.16592
2006	5.08438
2007	4.15201
2008	8.61574
2009	-0.0837
2010	3.00503
2011	11.3665
2012	26.5255
2013	19.67086
2014	9.32194
2015	10.35722
2016	5.72099
2017	11.7065