Year	Number
2004-01-01	50
2005-01-01	48
2006-01-01	41
2007-01-01	40
2008-01-01	39
2009-01-01	37
2010-01-01	35
2011-01-01	34
2012-01-01	34
2013-01-01	34
2014-01-01	33
2015-01-01	32
2016-01-01	32
2017-01-01	32