Year	Number
2004-01-01	39
2005-01-01	40
2006-01-01	43
2007-01-01	45
2008-01-01	47
2009-01-01	51
2010-01-01	52
2011-01-01	57
2012-01-01	60
2013-01-01	63
2014-01-01	58
2015-01-01	52
2016-01-01	51