Year	Number
2004-01-01	23
2005-01-01	26
2006-01-01	26
2007-01-01	27
2008-01-01	27
2009-01-01	26
2010-01-01	28
2011-01-01	27
2012-01-01	28
2013-01-01	28
2014-01-01	28
2015-01-01	28
2016-01-01	28