Year	Number
2004-01-01	4
2005-01-01	6
2006-01-01	10
2007-01-01	13
2008-01-01	15
2009-01-01	16
2010-01-01	15
2011-01-01	23
2012-01-01	23
2013-01-01	37
2014-01-01	44