Year Number 2005-01-01 374 2006-01-01 405 2007-01-01 453 2008-01-01 471 2009-01-01 450 2010-01-01 462 2011-01-01 461 2012-01-01 577 2013-01-01 557 2014-01-01 584 2015-01-01 601 2016-01-01 636 2017-01-01 602