Year Percent 1991 2.026 1992 2.21 1993 2.242 1994 2.125 1995 2.045 1996 1.901 1997 1.805 1998 1.799 1999 1.701 2000 1.466 2001 1.1 2002 1.223 2003 1.079 2004 1.016 2005 0.963 2006 1.03 2007 1.378 2008 1.274 2009 1.447 2010 1.557 2011 1.532 2012 1.642 2013 1.869 2014 1.667 2015 1.557 2016 1.536 2017 1.607 2018 1.617 2019 1.607 2020 1.587 2021 1.581 2022 1.572