Year	Percent
1961	4.98136
1962	2.1488
1963	4.28214
1964	3.27317
1965	97.16301
1966	2.11715
1967	0.47319
1968	-0.77525
1969	15.1482
1970	-13.93638
1971	-9.47897
1972	10.14965
1973	7.19748
1974	52.47956
1975	5.57583
1976	9.49371
1977	19.36072
1978	2.2899
1979	14.61446
1980	21.63569
1981	15.49145
1982	-9.18217
1983	-13.64483
1984	-3.92135
1985	-2.44014
1986	-13.69042
1987	-8.70101
1988	-11.6138
1989	5.36798
1990	5.81363
1991	6.88932
1992	4.30323
1993	2.64177
1994	15.00872
1995	5.22255
1996	1.49015
1997	7.00617
1998	-3.78268
1999	-26.29999
2000	-7.71407
2001	28.41428
2002	12.08527
2003	10.59309
2004	4.26185
2005	7.73271
2006	8.00091
2007	6.6505
2008	13.84732
2009	0.65554
2010	7.46508
2011	5.66266
2012	4.98525
2013	3.09505
2014	3.0307
2015	-2.49102
2016	0.90947
2017	1.46307