Year % 2000 0.380033285501351 2001 0.371894210749251 2002 0.35979402058072 2003 0.365697000041084 2004 0.327769245425799 2005 0.393209155537626 2006 0.368758402455241 2007 0.343271471135328 2008 0.320091836458657 2009 0.354611267812153 2010 0.345992463149718 2011 0.326819395916546 2012 0.307213692578778 2013 0.292772912804489 2014 0.267646033204212 2015 0.307880819960795 2016 0.307441866468971 2017 0.307988287660602 2018 0.24733282744186 2019 0.238887178143983 2020 0.241702983996239