Year Number 2004-01-01 680 2005-01-01 666 2006-01-01 654 2007-01-01 649 2008-01-01 641 2009-01-01 640 2010-01-01 636 2011-01-01 633 2012-01-01 628 2013-01-01 626 2014-01-01 616 2015-01-01 610 2016-01-01 599