Year	Number
2004-01-01	43
2005-01-01	40
2006-01-01	37
2007-01-01	35
2008-01-01	35
2009-01-01	37
2010-01-01	37
2011-01-01	38
2012-01-01	38
2013-01-01	35
2014-01-01	35
2015-01-01	36
2016-01-01	37
2017-01-01	36