Year	Number
2004-01-01	56
2005-01-01	53
2006-01-01	53
2007-01-01	52
2008-01-01	53
2009-01-01	56
2010-01-01	57
2011-01-01	58
2012-01-01	58
2013-01-01	60
2014-01-01	62
2015-01-01	59
2016-01-01	60
2017-01-01	63