Year	Number
2006-01-01	57
2007-01-01	57
2008-01-01	53
2009-01-01	56
2010-01-01	56
2011-01-01	56
2012-01-01	51
2013-01-01	51
2014-01-01	51
2015-01-01	53
2016-01-01	52