Year Number 2004-01-01 3835 2005-01-01 1600 2006-01-01 3600 2007-01-01 7300 2008-01-01 8500 2009-01-01 9500 2010-01-01 11091 2011-01-01 11630 2012-01-01 15904 2013-01-01 20982 2014-01-01 18049 2015-01-01 26540 2016-01-01 26540