Year	Number
2004-01-01	20
2005-01-01	25
2006-01-01	23
2007-01-01	23
2008-01-01	21
2009-01-01	18
2010-01-01	18
2011-01-01	14
2012-01-01	12
2013-01-01	10
2014-01-01	10
2015-01-01	11
2016-01-01	8