Year Number 2005-01-01 35 2006-01-01 42 2007-01-01 255 2008-01-01 293 2009-01-01 281 2010-01-01 329 2011-01-01 376 2012-01-01 374 2013-01-01 478 2014-01-01 551 2015-01-01 564 2016-01-01 501 2017-01-01 527