Year Percent 1992-01-01 1.2491100000000000 1993-01-01 1.3103799999999999 1994-01-01 1.2161400000000000 1995-01-01 1.4038500000000000 1996-01-01 1.4579000000000000 1997-01-01 1.3614500000000000 1998-01-01 1.2586600000000001 1999-01-01 1.2131600000000000 2000-01-01 1.1909100000000001 2001-01-01 1.2478900000000000 2002-01-01 1.5098300000000000 2003-01-01 1.6687299999999998 2004-01-01 1.7111299999999998 2005-01-01 1.7984500000000000 2006-01-01 1.7862200000000001 2007-01-01 1.7358300000000000 2008-01-01 1.4866500000000000 2009-01-01 1.4673000000000000 2010-01-01 1.4162700000000001 2011-01-01 1.3942700000000001 2012-01-01 1.3860299999999999 2013-01-01 1.3265500000000000 2014-01-01 1.3012900000000000 2015-01-01 1.2605000000000000