Year	Percent
1977	0.22762
1978	0.0075
1979	0.06893
1980	1.04131
1981	1.10233
1982	0.87146
1983	1.24181
1984	0.69379
1985	0
1986	0.6464
1987	1.40849
1988	4.4704
1989	2.69886
1990	2.86385
1991	1.06025
1992	0.32096
1993	1.79249
1994	2.13324
1995	27.48234
1996	30.38665
1997	26.86798
1998	28.51997
1999	17.89503
2000	3.65199
2001	3.59634
2002	3.6597
2003	3.79572
2004	3.68383
2005	1.63114
2006	1.35116
2007	4.15287
2008	0.58854
2009	4.89557
2010	0.39847
2011	2.19415
2012	2.11512
2013	1.99638
2014	3.61279
2015	4.51817
2016	3.42501
2017	1.6353