Year Number 2004-01-01 0.8273 2005-01-01 0.7531 2006-01-01 0.7531 2007-01-01 0.7531 2008-01-01 0.7531 2009-01-01 0.7531 2010-01-01 0.8273 2011-01-01 0.8273 2012-01-01 0.8061 2013-01-01 0.8273 2014-01-01 0.8061 2015-01-01 0.8167