Year Percent 1990 9.562 1991 10.2 1992 9.604 1993 9.039 1994 8.504 1995 7.998 1996 7.519 1997 7.067 1998 6.641 1999 6.238 2000 5.858 2001 5.5 2002 5.11 2003 5.53 2004 6.23 2005 5.63 2006 5.83 2007 4.42 2008 5.1 2009 5.04 2010 4.44 2011 4.33 2012 3.59 2013 2.72 2014 2.57 2015 2.46 2016 1.76 2017 1.706 2018 1.653 2019 1.599 2020 1.546 2021 1.492 2022 1.438 2023 1.385 2024 1.331 2025 1.278 2026 1.224 2027 1.17 2028 1.117 2029 1.063 2030 1.01