Year Percent 1990 4.66 1991 4.41 1992 2.45 1993 4.13 1994 2.5 1995 2.06 1996 2.15 1997 3.64 1998 4.31 1999 3.76 2000 5.46 2001 2.88 2002 4.53 2003 4.12 2004 6.88 2005 3.8 2006 5.59 2007 6.23 2008 4.29 2009 4.38 2010 3.81 2011 3.92 2012 4.32 2013 3.73 2014 3.7 2015 3.33 2016 3.08 2017 2.88 2018 2.44 2019 2.24 2020 2.25