Year	Number
2004-01-01	22
2005-01-01	22
2006-01-01	22
2007-01-01	23
2008-01-01	23
2009-01-01	23
2010-01-01	24
2011-01-01	24
2012-01-01	24
2013-01-01	27
2014-01-01	27
2015-01-01	25