Year	Percent
1966	2.41967
1967	61.65744
1968	76.67469
1969	21.87713
1970	10.25616
1971	-2.48596
1972	5.94787
1973	-17.50435
1974	6.86947
1975	18.777
1976	14.64009
1977	-4.19588
1978	-8.82142
1979	-1.31105
1980	0.29212
1981	10.69812
1982	5.55735
1983	10.58209
1984	11.00437
1985	8.88363
1986	-2.09887
1987	-6.93861
1988	2.28573
1989	7.71036
1990	-4.04329
1991	1.50288
1992	3.52113
1993	1.49677
1994	0.18587
1995	2.33627
1996	1.55402
1997	5.41577
1998	2.54653
1999	-0.25959
2000	4.79383
2001	3.26242
2002	-2.77402
2003	-4.74882
2004	-1.17295
2005	-0.22429
2006	2.4462
2007	1.3235
2008	4.425
2009	1.55104
2010	-0.65761
2011	-7.09024
2012	2.15744
2013	-2.56882
2014	-3.71984
2015	-1.21859
2016	0.0265
2017	-4.8221