Year Percent 1990 89.143 1991 89.145 1992 89.048 1993 87.236 1994 85.579 1995 85.07 1996 84.566 1997 83.169 1998 82.341 1999 85.049 2000 85.25 2001 84.412 2002 85.148 2003 85.008 2004 85.492 2005 85.807 2006 86.483 2007 86.62 2008 85.992 2009 85.858 2010 86.001 2011 86.266 2012 86.593 2013 85.683 2014 85.998 2015 85.844 2016 86.667 2017 86.882 2018 87.123 2019 87.376 2020 87.631 2021 87.891 2022 88.159 2023 88.428 2024 88.693 2025 88.946 2026 89.185 2027 89.403 2028 89.599 2029 89.771 2030 89.92