Year Percent 1991 16.781 1992 10.297 1993 8.065 1994 7.35 1995 9.207 1996 12.872 1997 8.061 1998 9.094 1999 11.158 2000 6.887 2001 10.113 2002 10.349 2003 6.117 2004 5.79 2005 4.9 2006 5.99 2007 6.136 2008 5.603 2009 5.107 2010 5.207 2011 5.078 2012 5.472 2013 5.02 2014 4.945 2015 5.582 2016 6.125 2017 5.951 2018 5.921 2019 5.923 2020 5.914 2021 5.904 2022 5.861