Year Number 1996 1.28849947452545 1998 1.24214780330658 2000 1.41133570671082 2002 1.09601747989655 2003 0.577859222888947 2004 0.638884365558624 2005 0.888915359973907 2006 1.02506959438324 2007 0.995823800563812 2008 0.943830788135529 2009 0.859902501106262 2010 0.796834468841553 2011 0.842218458652496 2012 0.775621294975281 2013 0.92798388004303 2014 0.925186455249786 2015 0.687514960765839 2016 0.667541146278381 2017 0.574380218982697 2018 0.577707588672638 2019 0.548454642295837 2020 0.644988059997559 2021 0.725666701793671 2022 0.614759147167206