Year Percent 1990-01-01 0.63736900000000000 1991-01-01 0.64356099999999990 1992-01-01 0.59320699999999990 1993-01-01 0.59037100000000000 1994-01-01 0.54887800000000000 1995-01-01 0.53959300000000000 1996-01-01 0.45607600000000004 1997-01-01 0.48029300000000000 1998-01-01 0.45297000000000000 1999-01-01 0.44473400000000000 2000-01-01 0.54749500000000000 2001-01-01 0.51925600000000000 2002-01-01 0.54215300000000000 2003-01-01 0.55882400000000000 2004-01-01 0.56210799999999990 2005-01-01 0.51284300000000000 2006-01-01 0.52654100000000000 2007-01-01 0.53303100000000000 2008-01-01 0.49835300000000000 2009-01-01 0.46924899999999997 2010-01-01 0.46827500000000000 2011-01-01 0.46226000000000006 2012-01-01 0.38760900000000004 2013-01-01 0.39116400000000000 2014-01-01 0.45861199999999996 2015-01-01 0.46779899999999996