Year	Percent
1970	0.12774
1971	0.05962
1972	0
1973	0
1974	0
1975	-0.01303
1976	0.03953
1977	0.03455
1978	0.04158
1979	0.00465
1980	-0.01242
1981	0.44429
1982	0.68066
1983	0.3224
1984	0.08268
1985	0.34881
1986	0.37261
1987	0.40858
1988	0.29394
1989	0.21932
1990	0.33804
1991	0.49015
1992	0.76678
1993	0.81022
1994	0.85926
1995	0.81739
1996	0.74129
1997	0.80427
1998	0.9694
1999	0.70757
2000	2.52026
2001	0.52584
2002	0.81011
2003	1.64403
2004	3.35258
2005	2.06742
2006	10.02676
2007	4.81487
2008	3.34006
2009	0.84423
2010	3.40029
2011	2.82878
2012	0.88443
2013	1.31909
2014	1.46733
2015	3.66721
2016	4.58804
2017	1.75368