Year	Number
2004-01-01	43
2005-01-01	40
2006-01-01	37
2007-01-01	35
2008-01-01	34
2009-01-01	34
2010-01-01	33
2011-01-01	33
2012-01-01	32
2013-01-01	30
2014-01-01	29
2015-01-01	30
2016-01-01	31
2017-01-01	29