Year	Number
2004-01-01	60
2005-01-01	57
2006-01-01	54
2007-01-01	48
2008-01-01	49
2009-01-01	48
2010-01-01	49
2011-01-01	59
2012-01-01	58
2013-01-01	58
2014-01-01	59
2015-01-01	59
2016-01-01	58
2017-01-01	58