Year Percent 1990 1.28348 1991 1.30132 1992 1.13171 1993 1.07502 1994 1.04222 1995 1.07036 1996 1.0452 1997 1.02064 1998 1.007 1999 0.97306 2000 0.94128 2001 0.9109 2002 0.88187 2003 0.85918 2005 0.82619 2006 0.81965 2007 0.80313 2008 0.76688 2009 0.74485 2010 0.74153 2011 0.74467 2012 0.71032 2013 0.68771 2014 0.67471 2015 1.21572 2016 1.18607 2017 1.3789 2018 1.32226 2019 1.37156 2020 1.40961