Year Number 2004-01-01 135 2005-01-01 170 2006-01-01 159 2007-01-01 152 2008-01-01 147 2009-01-01 194 2010-01-01 199 2011-01-01 212 2012-01-01 230 2013-01-01 280 2014-01-01 396 2015-01-01 467 2016-01-01 535