Year Number 2007-01-01 13458 2008-01-01 18839 2009-01-01 25645 2010-01-01 30376 2011-01-01 32562 2012-01-01 26187 2013-01-01 27633 2014-01-01 43306 2015-01-01 20913 2016-01-01 21964