Year	Number
2004-01-01	56
2005-01-01	56
2006-01-01	48
2007-01-01	41
2008-01-01	35
2009-01-01	31
2010-01-01	32
2011-01-01	28
2012-01-01	13
2013-01-01	16
2014-01-01	16
2015-01-01	13
2016-01-01	13