Year Percent 1990 8.03 1991 8.697 1992 9.415 1993 10.185 1994 11.01 1995 11.893 1996 12.837 1997 13.843 1998 14.916 1999 16.056 2000 17.265 2001 17.039 2002 16.816 2003 16.595 2004 16.376 2005 16.16 2006 15.946 2007 15.734 2008 15.525 2009 15.318 2010 15.113 2011 15.173 2012 15.195 2013 15.191 2014 15.182 2015 15.18 2016 15.174 2017 15.072 2018 14.971 2019 14.869 2020 14.768 2021 14.666 2022 14.565 2023 14.463 2024 14.362 2025 14.26 2026 14.159 2027 14.057 2028 13.956 2029 13.854 2030 13.753