Year Number 2004-01-01 836 2005-01-01 835 2006-01-01 827 2007-01-01 819 2008-01-01 815 2009-01-01 804 2010-01-01 796 2011-01-01 778 2012-01-01 764 2013-01-01 747 2014-01-01 722 2015-01-01 697 2016-01-01 631 2017-01-01 589