Year Percent 1990 74.3 1991 73.757 1992 74.99 1993 74.204 1994 74.12 1995 75.152 1996 76.206 1997 76.858 1998 78.61 1999 77.713 2000 78.014 2001 79.469 2002 80.642 2003 80.549 2004 80.802 2005 81.326 2006 81.214 2007 81.931 2008 83.623 2009 83.931 2010 81.958 2011 82.884 2012 83.638 2013 83.604 2014 84.801 2015 84.869 2016 85.553 2017 85.741 2018 85.929 2019 86.116 2020 86.303 2021 86.486 2022 86.665 2023 86.841 2024 87.017 2025 87.195 2026 87.375 2027 87.559 2028 87.749 2029 87.941 2030 88.137