Year	Percent
1961	0.20243
1962	0.89242
1963	1.29002
1964	-0.64553
1965	-1.22434
1966	-6.44761
1967	0.94602
1968	-1.62821
1969	3.78026
1970	7.17551
1971	2.4712
1972	-5.23904
1973	-0.04828
1974	4.0248
1975	-14.45469
1976	-5.37869
1977	0.6038
1978	6.75146
1979	-4.32847
1980	-1.86524
1981	-6.24217
1982	-9.92544
1983	-7.82931
1984	4.97602
1985	1.74397
1986	2.08381
1987	1.86351
1988	2.78578
1989	2.28292
1990	0.54302
1991	2.40291
1992	1.02889
1993	1.99679
1994	0.55627
1995	1.43953
1996	2.01478
1997	1.69214
1998	2.21773
1999	1.90764
2000	1.17495
2001	1.41444
2002	1.8623
2003	2.51294
2004	2.88407
2005	3.16931
2006	3.65051
2007	1.64952
2008	6.34628
2009	2.19006
2010	5.22216
2011	11.27926
2012	6.69669
2013	4.81485
2014	1.60895
2015	1.50205
2016	1.42767
2017	6.14799