Year Number 1996 0.551819324493408 1998 0.922752976417542 2000 0.697727382183075 2002 0.441433399915695 2003 0.623164057731628 2004 0.546658217906952 2005 0.594156503677368 2006 0.382123380899429 2007 0.450156897306442 2008 0.566187620162964 2009 0.518184363842011 2010 0.586027026176453 2011 0.596260905265808 2012 0.743631064891815 2013 0.747273743152618 2014 0.656426250934601 2015 0.664466142654419 2016 0.526479542255402 2017 0.433457106351852 2018 0.476172715425491 2019 0.544661998748779 2020 0.477579593658447 2021 0.438738018274307 2022 0.567061722278595