Year Percent 1983 5.07 1984 2.64 1986 1.02 1988 1.37 1989 1.17 1990 1.45 1991 1.48 1992 2.02 1993 0.73 1994 1.62 1995 0.97 1996 3.156 1997 2.06 1998 1.466 1999 3.927 2000 4.344 2001 3.101 2002 3.893 2003 3.437 2004 2.614 2005 2.822 2006 3.723 2007 2.519 2008 2.941 2009 4.312 2010 3.4445 2011 3.0912 2012 2.4829 2013 2.3635 2014 3.3682 2015 2.7003 2016 2.7845 2017 2.8175