Year Percent 1996-01-01 44.302300000000000 1997-01-01 47.141000000000005 1998-01-01 46.789300000000000 1999-01-01 50.450600000000000 2000-01-01 51.438700000000000 2001-01-01 35.516000000000000 2002-01-01 56.318000000000005 2003-01-01 73.738700000000000 2004-01-01 76.172500000000000 2005-01-01 71.565600000000000 2006-01-01 63.544700000000000 2007-01-01 57.836900000000000 2008-01-01 58.246900000000000 2009-01-01 57.341400000000000 2010-01-01 61.858700000000000 2011-01-01 59.397900000000000 2012-01-01 57.663900000000000 2013-01-01 58.458999999999996 2014-01-01 61.539100000000000