Year Percent 1996-01-01 3.7404900000000003 1997-01-01 3.9860000000000000 1998-01-01 3.7441900000000000 1999-01-01 3.8028800000000005 2000-01-01 3.9278800000000005 2001-01-01 3.9426400000000004 2002-01-01 3.8895000000000000 2003-01-01 3.8809099999999996 2004-01-01 3.7298600000000000 2005-01-01 3.4879200000000000 2006-01-01 3.4223600000000000 2007-01-01 3.1873500000000000 2008-01-01 3.0427500000000000 2009-01-01 3.0567000000000000 2010-01-01 2.7394300000000000 2011-01-01 2.7228800000000000 2012-01-01 2.6617599999999997 2013-01-01 2.6076000000000000 2014-01-01 2.6610099999999997 2015-01-01 3.4730000000000003 2016-01-01 3.3635699999999997