Year Percent 1992 0.73025 1993 1.04588 1994 0.87893 1995 1.22187 1996 1.20526 1997 1.13566 1998 1.11565 1999 1.06976 2000 0.97902 2001 0.88449 2002 0.81357 2003 0.86238 2004 0.7792 2005 0.8793 2006 0.73958 2007 0.85748 2008 0.77017 2009 0.77056 2010 0.79176 2011 0.78023 2012 0.80885 2013 0.79573 2014 0.76254 2015 0.73167 2016 0.73913 2017 0.71092 2018 0.65155 2019 0.6618 2020 0.70281