Year	Number
2004-01-01	9
2005-01-01	21
2006-01-01	54
2007-01-01	125
2008-01-01	223
2009-01-01	281
2010-01-01	309
2011-01-01	317
2012-01-01	325
2013-01-01	342
2014-01-01	351
2015-01-01	414
2016-01-01	528