Year Percent 1990 1.06705 1991 1.03318 1992 0.9575 1993 0.93139 1994 1.00895 1995 1.185 1996 1.16372 1997 1.15792 1998 1.13332 1999 0.94364 2000 0.76409 2001 0.75312 2002 0.79124 2003 0.79493 2004 0.72523 2005 0.72585 2006 1.0282 2007 1.02573 2008 1.02785 2009 0.64304 2010 0.64489 2011 0.56977 2012 0.59894 2013 0.60343 2014 0.60034 2015 0.57333 2016 0.54768 2017 0.50565 2018 0.48491 2019 0.49471 2020 0.49534