Year	Number
2004-01-01	0.1487
2005-01-01	0.3303
2006-01-01	0.3871
2007-01-01	0.1153
2008-01-01	0.1434
2009-01-01	0.1085
2010-01-01	0.0617
2011-01-01	0.0010
2012-01-01	0.0008