Year	Number
2004-01-01	0
2005-01-01	0
2006-01-01	0
2007-01-01	0
2008-01-01	13669
2009-01-01	14549
2010-01-01	18656
2011-01-01	25822
2012-01-01	25020
2013-01-01	22993