Year	Percent
1961	-3.65583
1962	2.09156
1963	0.4036
1964	4.08311
1965	10.58906
1966	23.64185
1967	0.26287
1968	15.93991
1969	22.94621
1970	-11.39441
1971	-7.49652
1972	3.71051
1973	19.88985
1974	10.82215
1975	-14.1699
1976	15.20459
1977	8.25402
1978	12.68149
1979	21.88907
1980	11.76292
1981	7.15862
1982	6.1386
1983	18.62935
1984	18.33123
1985	41.13735
1986	81.98836
1987	62.0129
1988	34.4903
1989	80.87733
1990	106.38892
1991	92.65458
1992	165.53395
1993	143.65834
1994	80.7422
1995	30.61112
1996	24.34926
1997	25.40254
1998	16.90687
1999	17.92387
2000	32.61387
2001	25.33126
2002	19.39092
2003	17.60772
2004	19.71682
2005	16.6502
2006	14.54225
2007	12.97021
2008	10.64024
2009	5.55969
2010	13.95091
2011	11.11506
2012	6.99064
2013	9.72727
2014	5.43793
2015	6.66025
2016	13.57377
2017	9.23841