Year Percent 1991 62.135 1992 61.953 1993 61.935 1994 61.917 1995 61.898 1996 61.861 1997 61.82 1998 61.773 1999 61.73 2000 61.713 2001 61.672 2002 61.685 2003 62.098 2004 62.793 2005 63.478 2006 63.22 2007 62.944 2008 62.661 2009 62.402 2010 62.705 2011 63.024 2012 63.459 2013 64.672 2014 64.722 2015 64.764 2016 64.692 2017 64.706 2018 64.726 2019 64.756 2020 64.798 2021 64.844 2022 64.899