Year Percent 1991 9.728 1992 9.688 1993 10.141 1994 10.883 1995 9.009 1996 9.368 1997 9.351 1998 9.42 1999 9.284 2000 10.05 2001 9.812 2002 12.583 2003 12.699 2004 12.815 2005 13.212 2006 12.919 2007 13.11 2008 13.411 2009 13.051 2010 12.617 2011 11.68 2012 12.623 2013 12.217 2014 11.94 2015 11.655 2016 10.762 2017 10.814 2018 10.792 2019 10.733 2020 10.571 2021 10.442 2022 10.341