Year	Number
2004-01-01	25
2005-01-01	26
2006-01-01	27
2007-01-01	27
2008-01-01	28
2009-01-01	28
2010-01-01	29
2011-01-01	29
2012-01-01	30
2013-01-01	30
2014-01-01	30
2015-01-01	31