Year	Number
2004-01-01	37
2005-01-01	36
2006-01-01	36
2007-01-01	34
2008-01-01	33
2009-01-01	33
2010-01-01	31
2011-01-01	31
2012-01-01	31
2013-01-01	31
2014-01-01	31
2015-01-01	31
2016-01-01	31
2017-01-01	31