Year	Number
2004-01-01	34
2005-01-01	35
2006-01-01	38
2007-01-01	43
2008-01-01	52
2009-01-01	56
2010-01-01	29
2011-01-01	31
2012-01-01	34
2013-01-01	23
2014-01-01	23
2015-01-01	18
2016-01-01	19
2017-01-01	22