Year Number 2004-01-01 50 2005-01-01 66 2006-01-01 65 2007-01-01 66 2008-01-01 68 2009-01-01 68 2010-01-01 69 2011-01-01 70 2012-01-01 70 2013-01-01 76 2014-01-01 76 2015-01-01 79 2016-01-01 80