Year	Number
2004-01-01	29
2005-01-01	22
2006-01-01	21
2007-01-01	24
2008-01-01	32
2009-01-01	37
2010-01-01	37
2011-01-01	41
2012-01-01	48
2013-01-01	48
2014-01-01	49
2015-01-01	48
2016-01-01	48