Year	Number
2004-01-01	43
2005-01-01	43
2006-01-01	41
2007-01-01	42
2008-01-01	44
2009-01-01	45
2010-01-01	43
2011-01-01	42
2012-01-01	38
2013-01-01	38
2014-01-01	36
2015-01-01	35
2016-01-01	31
2017-01-01	31