Year	Number
2004-01-01	53
2005-01-01	54
2006-01-01	56
2007-01-01	56
2008-01-01	57
2009-01-01	54
2010-01-01	54
2011-01-01	54
2012-01-01	52
2013-01-01	51
2014-01-01	50
2015-01-01	50
2016-01-01	50