Year	Number
2004-01-01	2
2005-01-01	2
2006-01-01	2
2007-01-01	2
2008-01-01	2
2009-01-01	2
2010-01-01	6
2011-01-01	6
2012-01-01	10
2013-01-01	10
2014-01-01	10