Year	Percent
1961	4.58047
1962	4.19614
1963	7.23988
1964	-6.11775
1965	5.01409
1966	8.1494
1967	9.83074
1968	11.67554
1969	12.02646
1970	12.12891
1971	10.04426
1972	11.44319
1973	9.07059
1974	4.71077
1975	3.09253
1976	5.99848
1977	6.00696
1978	7.39612
1979	8.04693
1980	8.6391
1981	5.4884
1982	2.5708
1983	7.13993
1984	6.7633
1985	-0.82265
1986	1.42342
1987	9.10374
1988	8.33082
1989	6.9955
1990	5.84664
1991	3.6941
1992	3.91826
1993	8.7511
1994	7.50018
1995	3.82562
1996	3.24912
1997	4.71566
1998	-5.49106
1999	5.25073
2000	7.02763
2001	-3.58825
2002	3.26494
2003	5.98667
2004	8.18626
2005	4.99207
2006	5.50629
2007	4.65932
2008	-3.48742
2009	-3.55639
2010	13.21649
2011	4.15632
2012	1.5608
2013	3.42272
2014	2.54374
2015	1.03526
2016	1.07707
2017	3.52678