Year	Number
2004-01-01	28
2005-01-01	28
2006-01-01	25
2007-01-01	22
2008-01-01	22
2009-01-01	22
2010-01-01	16
2011-01-01	15
2012-01-01	13
2013-01-01	12
2014-01-01	12
2015-01-01	8
2016-01-01	9
2017-01-01	8