Year	Number
2004-01-01	28
2005-01-01	28
2006-01-01	27
2007-01-01	27
2008-01-01	25
2009-01-01	26
2010-01-01	25
2011-01-01	26
2012-01-01	26
2013-01-01	26
2014-01-01	26
2015-01-01	28