Year Percent 1990 8.77 1991 8.54 1992 8.93 1993 7.48 1994 7.64 1995 8.2 1996 7.6 1997 7.65 1998 7.69 1999 7.95 2000 7.82 2001 7.18 2002 7.83 2003 8.86 2004 8.78 2005 9.14 2006 9.83 2007 10.03 2008 10.78 2009 10.67 2010 11.68 2011 11.93 2012 12.51 2013 13.23 2014 13.56 2015 14.21 2016 14.23 2017 14.45 2018 14.67 2019 14.889 2020 15.109 2021 15.329 2022 15.549 2023 15.768 2024 15.988 2025 16.208 2026 16.428 2027 16.647 2028 16.867 2029 17.087 2030 17.307