Year Percent 1990 1.86131 1991 1.77594 1992 1.67091 1993 1.42506 1994 2.55199 1995 2.16849 1996 2.16633 1997 2.06926 1998 1.84443 1999 1.75201 2000 1.72948 2001 1.68691 2002 1.66055 2003 1.70148 2004 1.6793 2005 1.7018 2006 1.65448 2007 1.6443 2008 1.64386 2009 1.65826 2010 1.64494 2011 1.66336 2012 1.67683 2013 1.50969 2014 1.4928 2015 1.41429 2016 1.43618 2017 0.99486 2018 0.99668 2019 0.98783 2020 1.00652