Year Number 2004-01-01 4170 2005-01-01 4487 2006-01-01 4734 2007-01-01 5029 2008-01-01 5321 2009-01-01 5499 2010-01-01 5704 2011-01-01 5895 2012-01-01 6139 2013-01-01 6137 2014-01-01 5650 2015-01-01 5785 2016-01-01 5834