Year	Number
2004-01-01	15
2005-01-01	15
2006-01-01	18
2007-01-01	18
2008-01-01	22
2009-01-01	26
2010-01-01	39
2011-01-01	45
2012-01-01	48
2013-01-01	48
2014-01-01	48
2015-01-01	56
2016-01-01	54