Year	Number
2004-01-01	7
2005-01-01	7
2006-01-01	6
2007-01-01	5
2008-01-01	4
2009-01-01	4
2010-01-01	3
2011-01-01	3
2012-01-01	3
2013-01-01	3
2014-01-01	3
2015-01-01	4
2016-01-01	4