Year Percent 1991 11.449 1992 11.902 1993 10.056 1994 10.281 1995 9.573 1996 11.109 1997 11.154 1998 10.167 1999 13.381 2000 10.583 2001 8.758 2002 13.052 2003 10.62 2004 11.157 2005 10.215 2006 9.16 2007 10.026 2008 9.401 2009 9.547 2010 9.488 2011 7.949 2012 7.037 2013 8.415 2014 9.654 2015 11.763 2016 11.443 2017 10.887 2018 10.384 2019 9.961 2020 9.642 2021 9.377 2022 9.167