Year	Number
2004-01-01	17
2005-01-01	19
2006-01-01	37
2007-01-01	21
2008-01-01	18
2009-01-01	19
2010-01-01	20
2011-01-01	23
2012-01-01	29
2013-01-01	38
2014-01-01	39
2015-01-01	50