Year	Number
2004-01-01	8
2005-01-01	8
2006-01-01	8
2007-01-01	8
2008-01-01	10
2009-01-01	11
2010-01-01	13
2011-01-01	17
2012-01-01	19
2013-01-01	18
2014-01-01	22
2015-01-01	28
2016-01-01	28