Year	Percent
1981	9.57798
1982	17.39335
1983	10.56382
1984	8.76659
1985	3.66666
1986	17.6934
1987	6.96239
1988	5.41161
1989	3.58486
1990	2.34531
1991	4.79242
1992	-4.11584
1993	49.35409
1994	-29.17246
1995	-1.5469
1996	-0.54614
1997	-0.83529
1998	-0.33599
1999	7.61208
2000	-7.9011
2001	5.15534
2002	-0.36321
2003	4.9211
2004	-6.33255
2005	-1.79488
2006	4.63977
2007	8.75142
2008	3.54593
2009	2.17462
2010	0.50509
2011	2.67641
2012	0.553
2013	1.42841
2014	-0.14677
2015	1.73627
2016	-0.83518
2017	1.1395