Year Number 1996 0.72334748506546 1998 0.82843679189682 2000 0.742288053035736 2002 0.837780058383942 2003 0.767004191875458 2004 0.700535595417023 2005 0.781813085079193 2006 0.846699059009552 2007 0.828915297985077 2008 0.780786275863647 2009 0.849935352802277 2010 0.79424387216568 2011 0.736775279045105 2012 0.775515556335449 2013 0.770423412322998 2014 0.849458038806915 2015 0.846551239490509 2016 0.842557549476624 2017 0.7974573969841 2018 0.792103886604309 2019 0.855667293071747 2020 0.869215667247772 2021 0.896955788135529 2022 0.933728396892548