Year Percent 1993 0.18824 1994 0.22714 1995 0.95348 1996 0.9633 1997 0.90737 1998 1.17607 1999 1.32021 2000 1.29669 2001 1.29421 2002 1.23377 2003 1.29394 2004 1.2607 2005 1.27419 2006 1.00351 2007 0.98028 2008 0.95265 2009 0.93139 2010 0.92256 2011 0.8013 2012 0.79596 2013 0.79094 2014 0.78612 2015 0.78168 2016 0.77756 2017 0.77904 2018 0.77476 2019 0.76956 2020 0.77314