Year Percent 1991 10.746 1992 10.151 1993 9.587 1994 9.101 1995 7.973 1996 8.534 1997 8.683 1998 7.895 1999 7.073 2000 6.363 2001 6.47 2002 6.145 2003 5.979 2004 6.974 2005 5.525 2006 6.234 2007 5.499 2008 5.691 2009 5.579 2010 5.755 2011 6.691 2012 6.301 2013 6.222 2014 5.064 2015 4.758 2016 5.066 2017 5.046 2018 4.981 2019 4.9 2020 4.809 2021 4.676 2022 4.508