Year Percent 1983 4.84 1984 2.64 1993 0.97 1994 1.36 1995 0.91 1996 4.59 1997 2 1998 1.86 1999 3.19 2000 4.56 2001 2.82 2002 3.57 2003 3.09 2004 3.77 2005 3.69 2006 4.56 2007 3.55 2008 5.4 2009 5.66 2010 3.01 2011 2.81 2012 2.44 2013 2.17 2014 3.06 2015 2.81 2016 2.61 2017 2.67 2018 2.35 2019 2.67 2020 4.45