Year Number 2004-01-01 477 2005-01-01 477 2006-01-01 472 2007-01-01 442 2008-01-01 426 2009-01-01 432 2010-01-01 422 2011-01-01 426 2012-01-01 417 2013-01-01 350 2014-01-01 292 2015-01-01 251 2016-01-01 246 2017-01-01 0