Year Number 2004-01-01 55 2005-01-01 54 2006-01-01 54 2007-01-01 54 2008-01-01 54 2009-01-01 54 2010-01-01 54 2011-01-01 52 2012-01-01 52 2013-01-01 52 2014-01-01 53