Year	Percent
1960	-0.05988
1961	-1.39216
1962	-1.99363
1963	-3.13225
1964	-0.28678
1965	-3.32237
1966	-3.60136
1967	-4.75039
1968	-0.76627
1969	0.64345
1970	1.84222
1971	-0.93549
1972	-0.64709
1973	-2.02157
1974	-7.23482
1975	-10.79724
1976	-7.96071
1977	-6.64427
1978	0.65486
1979	8.42291
1980	3.39765
1981	-4.15644
1982	-3.4335
1983	0.23364
1984	4.44295
1985	7.4114
1986	-1.63111
1987	-2.02007
1988	-3.02281
1989	0.12251
1990	1.92471
1991	-2.23298
1992	-2.93616
1993	-3.82939
1994	-3.38003
1995	-5.72745
1996	-5.02116
1997	-4.51503
1998	-5.54722
1999	-2.412
2000	-2.00128
2001	-1.86164
2002	-0.69957
2003	0.40472
2004	3.88839
2005	6.3402
2006	9.28822
2007	7.35612
2008	1.02149
2009	4.77218
2010	3.97952
2011	5.01724
2012	2.27933
2013	-0.17051
2014	-1.63681
2015	-2.58647
2016	-0.37832
2017	1.66