Year Number 1996 0.421002686023712 1998 0.301575392484665 2000 0.370262295007706 2002 0.208880379796028 2003 0.353011250495911 2004 0.369521200656891 2005 0.311570793390274 2006 0.155884757637978 2007 0.10320233553648 2008 0.112552218139172 2009 0.226648017764091 2010 0.37242180109024 2011 0.319815337657928 2012 0.386670023202896 2013 0.419104278087616 2014 0.553784787654877 2015 0.583111226558685 2016 0.676848351955414 2017 0.518894791603088 2018 0.46633306145668 2019 0.666612505912781 2020 0.778642654418945 2021 0.824829578399658 2022 0.747045457363129