Year Percent 1990 96.162 1991 96.151 1992 96.126 1993 96.135 1994 96.163 1995 96.16 1996 96.091 1997 95.998 1998 95.981 1999 96.035 2000 96.046 2001 95.919 2002 95.85 2003 95.812 2004 95.731 2005 95.65 2006 95.614 2007 95.628 2008 95.623 2009 95.705 2010 95.849 2011 96.05 2012 96.113 2013 96.217 2014 96.305 2015 96.324 2016 96.362 2017 96.385 2018 96.412 2019 96.433 2020 96.442 2021 96.375 2022 96.298 2023 96.221 2024 96.159 2025 96.118 2026 96.051 2027 95.995 2028 95.942 2029 95.881 2030 95.812