Year % 2000 0.485225360011071 2001 0.556471355138694 2002 0.472926166678415 2003 0.469676553832619 2004 0.471605441226786 2005 0.460489178963145 2006 0.455496254871215 2007 0.439361931582015 2008 0.365658726158595 2009 0.361521252928551 2010 0.360226650880477 2011 0.369032237825617 2012 0.355998398178004 2013 0.354810604526773 2014 0.275983150178541 2015 0.272192484872766 2016 0.266989028705369 2017 0.260270528504265 2018 0.254720609175455 2019 0.249960738605864 2020 0.242392089582353