Year	Percent
1966	1.33729
1967	-7.19449
1968	-0.27111
1969	-5.62339
1970	-4.50582
1971	0.36355
1972	-2.12996
1973	-10.45974
1974	-14.83181
1975	-13.39528
1976	2.66072
1977	-5.9592
1978	1.18784
1979	7.59631
1980	-24.81724
1981	-22.99536
1982	-16.27888
1983	5.57162
1984	0.46073
1985	-8.83624
1986	2.82325
1987	2.20304
1988	-14.28825
1989	22.41016
1996	-0.69512
1997	-2.51941
1998	-3.17059
1999	-7.84672
2000	-0.08772
2001	-2.07
2002	1.34351
2003	15.95242
2004	8.81472
2005	6.75504
2006	2.96866
2007	0.65052
2008	-3.27444
2009	-12.5679
2010	-8.20091
2011	2.99903
2012	0.20457
2013	-4.5524
2014	-4.38979
2015	-3.32622
2016	0.56292
2017	-4.8376