Year Percent 1990 82.256 1991 82.102 1992 83.521 1993 84.824 1994 84.779 1995 85.372 1996 85.046 1997 84.704 1998 84.795 1999 84.841 2000 84.737 2001 84.63 2002 84.512 2003 84.594 2004 85.213 2005 84.881 2006 84.504 2007 85.057 2008 86.98 2009 87.275 2010 86.841 2011 85.372 2012 86.071 2013 86.071 2014 85.493 2015 85.486 2016 85.441 2017 85.534 2018 85.632 2019 85.726 2020 85.813 2021 85.893 2022 85.967 2023 86.038 2024 86.104 2025 86.167 2026 86.225 2027 86.279 2028 86.334 2029 86.399 2030 86.479