Year Number 2004-01-01 20.7432 2005-01-01 20.7142 2006-01-01 20.6997 2007-01-01 20.6271 2008-01-01 20.5981 2009-01-01 20.5400 2010-01-01 20.4674 2011-01-01 25.6060 2012-01-01 25.4754 2013-01-01 24.9528 2014-01-01 24.7931 2015-01-01 24.9964 2016-01-01 24.8512 2017-01-01 24.5899