Year % 2000 4.18000937955295 2001 4.11661195831979 2002 3.84383986942576 2003 3.65759044906954 2004 3.52457749846609 2005 3.11151778778477 2006 2.92552914934325 2007 2.44028861765418 2008 2.27020613088181 2009 2.09920929736013 2010 1.77464101598364 2011 1.69159633748795 2012 1.41567446610099 2013 1.3598017000028 2014 1.15017558514773 2015 1.16150196338851 2016 0.980398017692058 2017 0.957754274442858 2018 0.933560870826654 2019 0.761067712175182 2020 0.696312160582492