Year	Number
2004-01-01	8
2005-01-01	8
2006-01-01	8
2007-01-01	10
2008-01-01	10
2009-01-01	34
2010-01-01	35
2011-01-01	35
2012-01-01	31
2013-01-01	31
2014-01-01	31
2015-01-01	30
2016-01-01	30
2017-01-01	30