Year Percent 1993-01-01 13.067000000000000 1994-01-01 15.885700000000000 1995-01-01 14.000700000000000 1996-01-01 11.735600000000000 1997-01-01 10.096600000000000 1998-01-01 11.241600000000000 1999-01-01 13.564400000000000 2000-01-01 13.371400000000000 2001-01-01 12.858800000000000 2002-01-01 14.246800000000000 2003-01-01 18.559800000000000 2004-01-01 24.609000000000000 2005-01-01 32.632800000000000 2006-01-01 42.503800000000000 2007-01-01 49.605700000000000 2008-01-01 58.107100000000000 2009-01-01 58.107100000000000 2010-01-01 57.722300000000000 2011-01-01 51.501000000000005 2012-01-01 46.913100000000000 2013-01-01 43.895600000000000 2014-01-01 41.150400000000000 2015-01-01 40.518800000000000 2016-01-01 41.400400000000000