Year Number 2004-01-01 2863 2005-01-01 3487 2006-01-01 4215 2007-01-01 4191 2008-01-01 5227 2009-01-01 6271 2010-01-01 8187 2011-01-01 9074 2012-01-01 10020 2013-01-01 8660 2014-01-01 13356 2015-01-01 19708