Year Number 1996 0.521090984344482 1998 0.282355040311813 2000 0.195348083972931 2002 0.393110811710358 2003 0.466075152158737 2004 0.458940267562866 2005 0.433445394039154 2006 0.449109822511673 2007 0.366876482963562 2008 0.247283861041069 2009 0.373885452747345 2010 0.39389044046402 2011 0.402631521224976 2012 0.379769444465637 2013 0.341402947902679 2014 0.524190723896027 2015 0.402314871549606 2016 0.387823909521103 2017 0.386965662240982 2018 0.529128134250641 2019 0.491362243890762 2020 0.572214603424072 2021 0.532973885536194 2022 0.561897993087769