Year	Number
2004-01-01	30
2005-01-01	31
2006-01-01	37
2007-01-01	40
2008-01-01	43
2009-01-01	41
2010-01-01	41
2011-01-01	42
2012-01-01	43
2013-01-01	48
2014-01-01	45
2015-01-01	44
2016-01-01	47