Year Number 1996 0.323560953140259 1998 0.333779960870743 2000 0.897578895092011 2002 0.89507007598877 2003 0.911131322383881 2004 0.460913151502609 2005 0.517324984073639 2006 0.567534446716309 2007 0.590501487255096 2008 0.509779751300812 2009 0.408267706632614 2010 0.264050841331482 2011 0.29826694726944 2012 0.335755437612534 2013 0.36694523692131 2014 0.230402737855911 2015 0.124421708285809 2016 0.40265017747879 2017 0.544383764266968 2018 0.391720503568649 2019 0.210106045007706 2020 0.297599732875824 2021 0.447897672653198 2022 0.320615470409393