Year Percent 1976 2.94 1978 1.79 1979 2.08 1980 1.82 1982 4.12 1984 8.91 1987 9.63 1988 5.28 1989 2.43 1990 4.28 1994 2.61 1996 2.46 1997 2.17 1998 7.44 1999 7.74 2000 6.56 2001 7.58 2003 5.03 2004 4.5 2005 4.76 2006 4.77 2007 4.47 2008 4.77 2009 5.6 2010 2.53 2011 2.88 2012 2.7 2013 1.21 2014 3.14 2015 3.1 2016 3.71 2017 4.36 2018 4 2019 4.16 2020 5.16