Year Percent 1990 71.776 1991 72.131 1992 72.483 1993 72.845 1994 72.979 1995 72.942 1996 73.121 1997 73.272 1998 73.286 1999 73.304 2000 73.366 2001 73.512 2002 73.565 2003 73.569 2004 73.542 2005 73.506 2006 73.626 2007 73.678 2008 73.695 2009 73.743 2010 73.733 2011 73.837 2012 73.894 2013 73.888 2014 73.818 2015 73.707 2016 73.703 2017 73.708 2018 73.705 2019 73.695 2020 73.68 2021 73.663 2022 73.644 2023 73.63 2024 73.624 2025 73.63 2026 73.647 2027 73.676 2028 73.721 2029 73.786 2030 73.873