Year Percent 1992 0.68687 1993 0.67484 1994 0.71041 1995 0.37456 1996 0.63526 1997 0.74432 1998 0.72715 1999 0.61097 2000 0.68909 2001 0.67865 2002 0.75342 2003 0.74069 2004 0.77773 2005 0.79448 2006 0.89664 2007 0.88617 2008 0.878 2009 0.85496 2010 0.84022 2011 0.82491 2012 0.8233 2013 0.83445 2014 0.82456 2015 0.81292 2016 0.81295 2017 0.8458 2018 0.84817 2019 0.82037 2020 0.82026