Year	Percent
1981	-0.49004
1982	1.01592
1983	1.17005
1984	4.31232
1985	3.92797
1986	7.3684
1987	1.79976
1988	0.49734
1989	1.00861
1990	9.87677
1991	37.26106
1992	4.46771
1993	16.39252
1994	16.85948
1995	89.47561
1996	161.82375
1997	12.08387
1998	74.1239
1999	24.84169
2000	14.77054
2001	64.3841
2002	17.89915
2003	27.76058
2004	7.72915
2005	9.36001
2006	4.65478
2007	9.50702
2008	-4.01963
2009	10.88796
2010	16.77451
2011	9.25952
2012	4.4005
2013	2.6567
2014	0.77232
2015	1.76964
2016	0.4792
2017	2.43518