Year Number 1996 1.17166376113892 1998 1.19583570957184 2000 1.07490420341492 2002 1.29533743858337 2003 1.1232738494873 2004 1.10752463340759 2005 1.15242898464203 2006 1.26175379753113 2007 1.42116558551788 2008 1.5237752199173 2009 1.41438210010529 2010 1.52651119232178 2011 1.55788862705231 2012 1.38360106945038 2013 1.36044573783875 2014 1.13593256473541 2015 1.01833045482635 2016 0.926982343196869 2017 0.885234951972961 2018 0.883697271347046 2019 0.955951392650604 2020 0.839920282363892 2021 0.699314296245575 2022 0.730678856372833