Year Percent 1990 1.39967 1991 1.35776 1992 1.34707 1993 1.30738 1994 0.98137 1995 1.58421 1996 1.54114 1997 1.33864 1998 1.06027 1999 1.02239 2000 1.28454 2001 1.19027 2002 1.15628 2003 1.12397 2004 1.03942 2005 1.01679 2006 0.72536 2007 0.70979 2008 0.69475 2009 0.66491 2010 0.65121 2011 0.77095 2012 0.70729 2013 0.74443 2014 0.7317 2015 0.71482 2016 0.6961 2017 0.67559 2018 0.66513 2019 0.66346 2020 0.67147