Year	Percent
1974	11.55637
1975	10.73895
1976	8.23358
1977	9.36117
1978	4.06738
1979	9.21718
1980	0.79482
1981	1.02486
1982	0.71716
1983	2.02631
1984	0.32186
1985	0.12142
1986	0.17166
1987	0.02759
1988	0.02093
1989	0.41955
1991	0.0598
1992	0.0449
1993	0.10559
1994	0.21412
1995	1.12845
1996	0.01553
1997	0.01745
1998	0.02407
1999	0.01665
2000	0.00944
2001	0.01582
2002	0.10014
2003	0.20306
2004	0.48525
2005	0.64283
2006	1.71739
2007	3.15935
2008	5.08917
2009	20.12975
2010	111.23249
2011	114.35862
2012	102.06678
2013	92.95016
2014	73.32502
2015	62.44735
2016	55.66583