Year	Percent
1961	-1.64633
1962	1.9004
1963	10.94833
1964	-7.93451
1965	8.21577
1966	-7.04939
1967	-8.15152
1968	9.36772
1969	0.80247
1970	2.46128
1971	1.65028
1972	0.0113
1973	-3.29899
1974	2.87321
1975	1.71995
1976	3.61885
1977	3.51548
1978	4.08514
1979	2.80894
1980	5.49373
1981	3.95874
1982	3.24862
1983	2.11001
1984	2.71447
1985	0.76922
1986	-2.97335
1987	-5.78265
1988	-12.90391
1989	2.00383
1990	1.26963
1991	-2.01074
1992	8.2904
1993	4.78755
1994	6.21364
1995	5.64806
1996	5.09249
1997	4.27481
1998	4.4807
1999	9.53333
2000	12.37387
2001	10.07235
2002	10.80824
2003	12.68542
2004	12.50443
2005	12.6111
2006	12.23379
2007	11.25097
2008	9.56862
2009	9.83758
2010	8.858
2011	4.76198
2012	6.42014
2013	7.45302
2014	7.00129
2015	6.01355
2016	4.90795
2017	5.40146