Year Percent 1991 4.905 1992 6.876 1993 6.998 1994 5.707 1995 6.23 1996 6.066 1997 5.647 1998 5.7 1999 5.055 2000 4.702 2001 4.796 2002 5.237 2003 5.922 2004 5.857 2005 4.752 2006 4.119 2007 3.886 2008 6.16 2009 5.643 2010 6.162 2011 6.168 2012 6.188 2013 6.011 2014 6.158 2015 5.87 2016 6.024 2017 5.991 2018 5.863 2019 5.824 2020 5.838 2021 5.829 2022 5.816