Year	Number
2004-01-01	3
2005-01-01	3
2006-01-01	7
2007-01-01	8
2008-01-01	12
2009-01-01	19
2010-01-01	20
2011-01-01	23
2012-01-01	23
2013-01-01	22
2014-01-01	18
2015-01-01	18
2016-01-01	16
2017-01-01	16