Year	Percent
1964	0.00004
1966	0.00004
1968	0.00004
1969	0.00004
1970	0.00006
1971	0.00005
1972	0.00004
1973	0.00003
1974	0.00005
1975	0.00005
1976	0.00003
1977	0.00003
1978	0.00003
1979	0.00003
1993	5.22609
1996	1.5468
1997	1.41085
1998	0.42845
1999	1.15815
2000	0.22026
2003	0.88065
2004	1.33661
2005	1.38079
2006	1.43463
2007	1.25408
2008	0.83306
2009	0.6701
2010	0.88989
2011	0.9716
2012	1.20667
2013	1.14618
2014	0.95025
2015	1.27815
2016	0.94869
2017	0.69877