Year	Percent
1961	1.58507
1962	4.00224
1963	6.16885
1964	5.30179
1965	2.40009
1966	-1.56287
1967	-1.96101
1968	0.12628
1969	4.19168
1970	3.09929
1971	1.08415
1972	-0.22531
1973	-1.48258
1974	0.25524
1975	6.53262
1976	12.05009
1977	10.25864
1978	3.31639
1979	3.51734
1980	7.33876
1981	1.19214
1982	7.15091
1983	4.65953
1984	3.32488
1985	3.76519
1986	-0.14339
1987	-0.29834
1988	2.44161
1989	2.23727
1990	3.11382
1991	-1.22683
1992	2.19996
1993	0.81833
1994	1.94324
1995	2.64101
1996	3.01766
1997	3.54932
1998	2.14189
1999	4.17496
2000	3.4397
2001	1.61512
2002	0.44803
2003	1.25093
2004	2.15683
2005	2.57896
2006	4.96603
2007	5.23463
2008	5.28244
2009	2.75574
2010	3.09167
2011	-0.34131
2012	-0.01428
2013	-0.08356
2014	0.66829
2015	2.18436
2016	2.26327
2017	2.19007