Year Percent 1990-01-01 1.5684600000000000 1991-01-01 1.6693099999999998 1992-01-01 1.8079400000000000 1993-01-01 1.7373400000000000 1994-01-01 1.8637800000000000 1995-01-01 1.8999599999999999 1996-01-01 2.0117700000000003 1997-01-01 1.8974400000000002 1998-01-01 1.7562799999999998 1999-01-01 1.6581800000000000 2000-01-01 1.5086700000000002 2001-01-01 1.6497900000000000 2002-01-01 1.7457099999999999 2003-01-01 1.7616100000000000 2004-01-01 1.6113700000000000 2005-01-01 1.5495299999999999 2006-01-01 1.4321500000000000 2007-01-01 1.3865700000000000 2008-01-01 1.2884500000000000 2009-01-01 1.4630800000000000 2010-01-01 1.3728100000000000 2011-01-01 1.3223200000000002 2012-01-01 1.3520100000000000 2013-01-01 1.3739299999999999 2014-01-01 1.3399700000000000 2015-01-01 1.3151500000000000 2016-01-01 1.2484600000000001