Year	Percent
1965	4.65116
1966	7.55718
1967	6.68421
1968	10.08311
1969	9.46545
1970	-2.75278
1971	-0.3291
1972	0.6089
1973	-0.35612
1974	3.15932
1975	-1.87206
1976	-4.93016
1977	-8.43104
1978	-7.77406
1979	-2.98768
1980	-5.36365
1981	-8.46708
1982	-10.52993
1983	-8.35553
1984	-11.36548
1985	-6.02995
1986	-7.11971
1987	-0.98938
1988	0.36025
1989	-3.31599
1990	-7.04716
1991	-4.95478
1992	-6.92991
1993	-7.52029
1994	-2.93984
1995	-3.90575
1996	-1.5016
1997	-2.27255
1998	-2.93989
1999	-1.94703
2000	-3.36252
2001	-3.91854
2002	-3.77248
2003	-3.4232
2004	-2.50601
2005	-0.38666
2006	-1.88384
2007	-1.90325
2008	-3.04752
2009	-2.7019
2010	-4.80045
2011	-7.217
2012	-9.21279
2013	-9.3165
2014	-10.98589
2015	-10.95277
2016	-10.66504
2017	-12.29196