Year Percent 1990 1.72774 1991 1.67706 1992 1.62795 1993 1.58559 1994 1.54593 1995 1.63812 1996 1.56646 1997 1.42224 1998 1.3508 1999 1.28497 2000 1.284 2001 1.22812 2002 1.17672 2003 1.12867 2004 0.98511 2005 0.94613 2006 0.90878 2007 0.87296 2008 0.83877 2009 0.84647 2010 0.81339 2011 0.7817 2012 0.75199 2013 0.72388 2014 0.6911 2015 0.95017 2016 0.91537 2017 1.19153 2018 0.86728 2019 1.12466 2020 1.12735