Year Percent 1994-01-01 20.696100000000000 1995-01-01 18.808000000000000 1996-01-01 16.912300000000000 1997-01-01 15.786800000000000 1998-01-01 17.485400000000000 1999-01-01 19.783400000000000 2000-01-01 21.206999999999997 2001-01-01 23.677400000000000 2002-01-01 26.261800000000000 2003-01-01 28.250400000000000 2004-01-01 31.663100000000000 2005-01-01 35.839300000000000 2006-01-01 39.623200000000000 2007-01-01 40.316800000000000 2008-01-01 40.200200000000000 2009-01-01 48.750900000000000 2010-01-01 48.313900000000000 2011-01-01 45.384800000000000 2012-01-01 45.038400000000000 2013-01-01 45.339200000000000 2014-01-01 44.751700000000000 2015-01-01 51.064800000000000 2016-01-01 58.711800000000000