Year	Number
2004-01-01	39
2005-01-01	36
2006-01-01	49
2007-01-01	52
2008-01-01	53
2009-01-01	53
2010-01-01	53
2011-01-01	54
2012-01-01	53
2013-01-01	52
2014-01-01	53
2015-01-01	55
2016-01-01	54
2017-01-01	52