Year	Number
2007-01-01	24
2008-01-01	24
2009-01-01	25
2010-01-01	24
2011-01-01	23
2012-01-01	22
2013-01-01	18
2014-01-01	19
2015-01-01	18
2016-01-01	21
2017-01-01	25