Year Number 2004-01-01 590 2005-01-01 560 2006-01-01 428 2007-01-01 427 2008-01-01 419 2009-01-01 404 2010-01-01 408 2011-01-01 397 2012-01-01 386 2013-01-01 378 2014-01-01 361 2015-01-01 352 2016-01-01 344 2017-01-01 342