Year Percent 1995 0.43496 1996 0.44069 1997 0.43363 1998 0.43917 1999 0.43683 2000 0.42246 2001 0.41495 2002 0.4186 2003 0.41149 2004 0.41314 2005 0.41103 2006 0.41832 2007 0.41598 2008 0.6799 2009 0.41288 2010 0.41105 2011 0.40904 2012 0.41546 2013 0.4099 2014 0.42541 2015 0.42239 2016 0.41026 2017 0.67978 2018 0.4177 2019 0.6953 2020 0.71321