Year	Percent
1961	3.69863
1962	0.5405
1963	-1.16674
1964	2.67778
1965	4.31657
1966	8.24533
1967	-1.66769
1968	-0.25299
1969	3.33337
1970	-4.9952
1971	-0.78632
1972	6.33694
1973	18.44564
1974	20.33469
1975	3.48802
1976	4.49709
1977	6.0147
1978	9.69718
1979	8.64558
1980	12.70248
1981	8.37242
1982	5.05785
1983	3.64916
1984	1.44787
1985	2.1772
1986	1.65316
1987	4.72321
1988	5.9184
1989	6.11674
1990	5.77318
1991	5.74652
1992	4.49045
1993	6.49194
1994	4.67246
1995	5.74016
1996	4.09786
1997	4.42092
1998	8.06375
1999	-2.57717
2000	1.3308
2001	1.91771
2002	1.69038
2003	2.14945
2004	3.56916
2005	5.0915
2006	5.10427
2007	2.47333
2008	5.13378
2009	0.19474
2010	4.08097
2011	3.74311
2012	1.90923
2013	1.77892
2014	1.44147
2015	0.85935
2016	2.36083
2017	2.31376