Year Percent 1990 1.30921 1991 1.26929 1992 1.3302 1993 1.29847 1994 1.26385 1995 1.24308 1996 1.21537 1997 1.17295 1998 1.10982 1999 1.10922 2000 1.11775 2001 1.11862 2002 1.08172 2003 1.04587 2004 0.76489 2005 0.76849 2006 0.89811 2007 0.90809 2008 0.89004 2009 0.91337 2010 0.91197 2011 0.90502 2012 0.86891 2013 0.86018 2014 0.57839 2015 0.53983 2016 0.51246 2017 0.50055 2018 0.50139 2019 0.50075 2020 0.54059