Year Number 2004-01-01 309 2005-01-01 309 2006-01-01 324 2007-01-01 329 2008-01-01 334 2009-01-01 333 2010-01-01 340 2011-01-01 342 2012-01-01 324 2013-01-01 323 2014-01-01 315 2015-01-01 312 2016-01-01 299 2017-01-01 288