Year Percent 1991 12.228 1992 12.53 1993 12.879 1994 12.629 1995 12.486 1996 12.846 1997 12.144 1998 12.534 1999 14.057 2000 12.672 2001 13.587 2002 11.925 2003 9.966 2004 8.583 2005 8.92 2006 11.438 2007 11.507 2008 11.952 2009 10.599 2010 11.189 2011 10.82 2012 12.624 2013 13.293 2014 11.352 2015 14.239 2016 11.77 2017 11.625 2018 11.37 2019 11.236 2020 11.167 2021 11.155 2022 11.195