Year	Percent
1967	-1.9597
1968	7.21445
1969	0.0173
1970	3.42764
1971	-2.86915
1972	-2.78854
1973	5.83317
1974	2.60071
1975	9.03761
1976	4.28144
1977	0.55131
1978	3.3181
1979	-4.24977
1980	2.89191
1981	-0.15438
1982	-4.25491
1983	6.76108
1984	-0.57984
1985	-5.0112
1986	-0.59255
1987	-2.32816
1988	-0.34704
1989	1.31828
1990	-0.47026
1991	-0.44228
1992	0.18938
1993	0.08629
1994	-2.59586
1995	-1.8993
1996	-0.61794
1997	1.97468
1998	0.57806
1999	3.33142
2000	2.3805
2001	2.58135
2002	-6.26417
2003	3.48877
2004	3.65313
2005	-4.07152
2006	-2.05113
2007	0.39272
2008	2.44287
2009	3.13926
2010	3.21565
2011	-7.26618
2012	2.33226
2013	1.56527
2014	-2.17921
2015	1.14936
2016	-0.83792
2017	0.44181