Year Ratio 1998-01-01 1.23275005817413 1999-01-01 1.23433995246887 2000-01-01 1.22307002544403 2002-01-01 1.20675003528595 2004-01-01 1.17227005958557 2005-01-01 1.19561994075775 2007-01-01 1.20568001270294 2008-01-01 1.18889999389648 2009-01-01 1.13385999202728 2010-01-01 1.12776994705200 2011-01-01 1.13196003437042 2012-01-01 1.12116003036499 2013-01-01 1.11652004718781 2014-01-01 1.10695004463196 2015-01-01 1.10236001014709 2016-01-01 1.09521996974945