Year	Number
2004-01-01	53
2005-01-01	54
2006-01-01	54
2007-01-01	54
2008-01-01	53
2009-01-01	53
2010-01-01	54
2011-01-01	54
2012-01-01	54
2013-01-01	56
2014-01-01	55
2015-01-01	53
2016-01-01	50
2017-01-01	49