Year	Number
2004-01-01	39
2005-01-01	37
2006-01-01	36
2007-01-01	34
2008-01-01	34
2009-01-01	34
2010-01-01	34
2011-01-01	35
2012-01-01	39
2013-01-01	38
2014-01-01	43
2015-01-01	44
2016-01-01	44
2017-01-01	52