Year	Percent
1961	3.27845
1962	1.38092
1963	-20.34281
1964	33.54059
1965	-3.05911
1966	4.13443
1967	6.22473
1968	6.46088
1969	4.95912
1970	-0.4202
1971	6.50417
1972	-7.27697
1973	34.75765
1974	65.41047
1975	4.37225
1976	14.66494
1977	9.79568
1978	2.85907
1979	18.98302
1980	36.7811
1981	10.44207
1982	16.90363
1983	2.92484
1984	12.01022
1985	-1.27605
1986	-20.80981
1987	0.99328
1988	2.61513
1989	7.72802
1990	15.35814
1991	-11.3661
1992	0.21387
1993	-0.50948
1994	46.55144
1995	1.33912
1996	13.56268
1997	0.94654
1998	-17.7864
1999	19.19134
2000	28.08934
2001	-0.16866
2002	0.85581
2003	-0.21712
2004	7.76528
2005	20.09446
2006	9.86816
2007	4.23135
2008	20.47895
2009	-18.07454
2010	16.56601
2011	12.68082
2012	-2.94317
2013	-6.15859
2014	-0.85057
2015	-8.92665
2016	-4.2621
2017	1.30309