Year	Percent
1988	-1.87731
1989	6.98603
1990	7.93533
1991	134.74952
1992	830.15961
1993	754.42792
1994	180.87493
1995	42.03109
1996	35.34291
1997	19.30964
1998	9.07751
1999	37.5745
2000	27.18222
2001	7.33236
2002	2.02544
2003	3.97497
2004	5.10843
2005	7.12862
2006	9.39162
2007	14.87655
2008	22.21599
2009	4.0353
2010	10.0339
2011	22.48184
2012	8.65632
2013	3.17519
2014	8.41523
2015	3.42729
2016	6.05056
2017	4.57562