Year Percent 1984 2.04302 1985 1.9046 1986 1.81193 1987 1.82756 1989 2.01251 1990 2.20853 1991 2.83373 1992 2.66301 1993 2.46129 1994 2.67508 1995 2.83415 1996 2.64691 1997 1.56182 1998 1.37856 1999 1.26759 2000 1.34465 2001 1.19863 2002 1.51332 2003 1.34722 2004 1.16175 2005 1.06444 2006 1.17042 2007 1.09339 2008 1.04313 2009 0.90964 2010 1.09749 2011 1.0923 2012 1.07272 2013 0.93502 2014 0.85104 2015 0.8267 2016 0.88675 2017 0.78263 2018 0.68676 2019 0.54523 2020 0.8273 2021 0.47625 2022 0.57221