Year Percent 2000 46.81421 2001 47.12043 2002 47.44092 2003 47.77522 2004 48.12342 2005 48.48441 2006 48.85949 2007 49.24695 2008 49.6487 2009 49.81032 2010 49.97738 2011 50.15053 2012 50.32917 2013 50.70513 2014 51.08356 2015 51.46509 2016 51.84972