Year	Number
2004-01-01	24
2005-01-01	24
2006-01-01	25
2007-01-01	24
2008-01-01	24
2009-01-01	24
2010-01-01	24
2011-01-01	22
2012-01-01	23
2013-01-01	24
2014-01-01	23
2015-01-01	22
2016-01-01	22