Year	Number
2004-01-01	6723
2005-01-01	8087
2006-01-01	8619
2007-01-01	10002
2008-01-01	10254
2010-01-01	18188
2011-01-01	24234
2012-01-01	24319
2013-01-01	24057
2015-01-01	24260