Year Percent 1990 0.97136 1991 0.94455 1992 0.92081 1993 0.8935 1994 0.86632 1995 1.48201 1996 1.78439 1997 1.73009 1998 1.68692 1999 1.64842 2000 1.61436 2001 1.50883 2002 1.48016 2003 1.47325 2004 0.98092 2005 1.01576 2006 1.08476 2007 1.0362 2008 1.0094 2009 0.96472 2010 0.97148 2011 0.94827 2012 0.88426 2013 0.8832 2014 0.88964 2015 0.8727 2016 0.83138 2017 0.86337 2018 0.88871 2019 0.86926 2020 0.88266