Year Percent 1991 46.236 1992 46.404 1993 46.53 1994 46.558 1995 46.399 1996 46.628 1997 46.735 1998 46.697 1999 46.63 2000 46.591 2001 46.695 2002 46.747 2003 46.796 2004 46.834 2005 46.863 2006 47.08 2007 47.204 2008 47.287 2009 47.38 2010 47.39 2011 47.585 2012 47.715 2013 47.772 2014 47.767 2015 47.708 2016 47.693 2017 47.729 2018 47.766 2019 47.812 2020 47.87 2021 47.941 2022 48.024