Year % 2000 0.519085316852717 2001 0.469074777292355 2002 0.424112382530632 2003 0.429295798182361 2004 0.428841506027156 2005 0.433052151390052 2006 0.433016970009624 2007 0.435284847275092 2008 0.384017145610863 2009 0.390809716891216 2010 0.413657490114891 2011 0.422641824336303 2012 0.384868053244202 2013 0.386080210910621 2014 0.410432107956851 2015 0.408140519360409 2016 0.418599123345422 2017 0.418996603852288 2018 0.429077635863797 2019 0.380503052130559 2020 0.387303761189798