Year Percent 1990 72.793 1991 72.767 1992 72.756 1993 72.756 1994 72.755 1995 72.736 1996 72.733 1997 72.74 1998 72.744 1999 72.743 2000 72.743 2001 72.714 2002 72.692 2003 72.68 2004 72.677 2005 72.683 2006 72.685 2007 72.697 2008 72.716 2009 72.739 2010 72.765 2011 72.781 2012 72.798 2013 72.819 2014 72.846 2015 72.882 2016 72.922 2017 72.993 2018 73.069 2019 73.146 2020 73.22 2021 73.294 2022 73.364 2023 73.434 2024 73.507 2025 73.587 2026 73.672 2027 73.761 2028 73.853 2029 73.943 2030 74.032