Year	Percent
1960	-4.80873
1961	-1.70118
1962	-1.90584
1963	0.12769
1964	-5.52035
1965	-3.58583
1966	1.58284
1967	-0.75776
1968	-5.23694
1969	-6.6989
1970	-4.18589
1971	-7.11946
1972	-8.2899
1973	-9.58195
1974	-10.23064
1975	-10.34841
1976	-8.84513
1977	1.38442
1978	3.22149
1979	-0.82482
1980	0.02724
1981	-8.61708
1982	-10.60149
1983	-7.33141
1984	-6.03195
1985	-9.83271
1986	2.95647
1987	0.33435
1988	-4.15523
1989	-8.78569
1990	-3.81382
1991	-1.18411
1992	-0.94524
1993	5.32633
1994	-0.28769
1995	-5.1002
1996	-7.22442
1997	-7.80635
1998	-7.60901
1999	-6.15853
2000	-11.93291
2001	-13.69942
2002	-16.32285
2003	-14.92369
2004	-14.23005
2005	-19.94142
2006	-20.48255
2007	-21.78704
2008	-29.69079
2009	-17.92595
2010	-18.25137
2011	-23.09245
2012	-21.68252
2013	-22.12567
2014	-22.23414
2015	-16.29419
2016	-13.56815
2017	-13.96853