Year	Percent
1981	18.91177
1982	13.72399
1983	-3.68997
1984	-0.41848
1985	-1.82499
1986	-17.39265
1987	0.65905
1988	2.00943
1989	3.97466
1990	4.8267
1991	-1.88252
1992	-3.53265
1993	-3.02581
1994	7.33119
1995	1.09067
1996	0.19672
1997	0.93172
1998	-7.05741
1999	2.65643
2000	29.99148
2001	-3.36388
2002	3.56464
2003	8.44494
2004	10.99108
2005	13.73499
2006	8.84253
2007	8.43544
2008	11.36485
2009	-12.99375
2010	7.44101
2011	9.73642
2012	3.01065
2013	0.38471
2014	-1.67061
2015	-9.36838
2016	0.08046
2017	5.70438