Year	Percent
1961	-0.90237
1962	0.85302
1963	1.47971
1964	1.23675
1965	-0.29632
1966	2.18686
1967	-13.02093
1968	3.78126
1969	2.32554
1970	0.51674
1971	0.85152
1972	0.02333
1973	2.58958
1974	7.77505
1975	8.21839
1976	-8.10848
1977	10.54684
1978	18.5249
1979	2.96358
1980	-4.8491
1981	13.5943
1982	4.28141
1983	3.6259
1984	4.19526
1985	4.75396
1986	3.49408
1987	-5.14707
1988	-10.62726
1989	-4.75745
1990	-8.85521
1991	-6.56425
1992	-5.81907
1993	-10.4573
1994	-0.60862
1995	0.76921
1996	1.70547
1997	2.60934
1998	1.9253
1999	1.71256
2000	0.96124
2001	1.71963
2002	1.56105
2003	1.85113
2004	3.97743
2005	-0.68325
2006	0.69044
2007	2.07468
2008	0.68842
2009	-0.56519
2010	0.63657
2011	1.33859
2012	1.75674
2013	2.6137
2014	3.10274
2015	2.90027
2016	1.75592
2017	0.54106