Year	Number
2004-01-01	4
2005-01-01	4
2006-01-01	4
2007-01-01	6
2008-01-01	16
2009-01-01	22
2010-01-01	30
2011-01-01	38
2012-01-01	49
2013-01-01	95
2014-01-01	172
2015-01-01	206