Year	Number
2004-01-01	47
2005-01-01	44
2006-01-01	44
2007-01-01	51
2008-01-01	52
2009-01-01	51
2010-01-01	47
2011-01-01	46
2012-01-01	45
2013-01-01	43
2014-01-01	42
2015-01-01	42
2016-01-01	41
2017-01-01	39