Year	Number
2004-01-01	3
2005-01-01	3
2006-01-01	3
2007-01-01	3
2008-01-01	9
2009-01-01	9
2010-01-01	9
2011-01-01	13
2012-01-01	27
2013-01-01	31
2014-01-01	32
2015-01-01	33