Year Percent 1990-01-01 4.8440400000000010 1991-01-01 4.7703500000000000 1992-01-01 3.9931400000000004 1993-01-01 4.6919600000000000 1994-01-01 4.6201900000000000 1995-01-01 3.8791000000000000 1996-01-01 4.3232200000000000 1997-01-01 4.7106800000000000 1998-01-01 5.6047199999999995 1999-01-01 6.2123200000000000 2000-01-01 7.0400399999999990 2001-01-01 5.8486199999999995 2002-01-01 5.7853699999999995 2003-01-01 5.1846800000000000 2004-01-01 5.8830200000000000 2005-01-01 5.9524099999999995 2006-01-01 7.2841700000000000 2007-01-01 8.3735600000000010 2008-01-01 6.0344600000000000 2009-01-01 5.7828000000000000 2010-01-01 5.8274300000000006 2011-01-01 4.9131800000000005 2012-01-01 5.3679700000000000 2013-01-01 6.0059100000000000 2014-01-01 5.5478900000000000 2015-01-01 4.5055600000000000