Year	Number
2004-01-01	9
2005-01-01	9
2006-01-01	10
2007-01-01	10
2008-01-01	11
2009-01-01	11
2010-01-01	13
2011-01-01	14
2012-01-01	15
2013-01-01	17
2014-01-01	30
2015-01-01	32
2016-01-01	34
2017-01-01	33