Year Number 1996 1.02049589157104 1998 0.624708473682404 2000 0.645909368991852 2002 0.607831418514252 2003 0.599580049514771 2004 0.559140086174011 2005 0.567057847976685 2006 0.325101375579834 2007 0.283431172370911 2008 0.332178503274918 2009 0.310807675123215 2010 0.191702410578728 2011 0.217559650540352 2012 0.170115306973457 2013 0.306189775466919 2014 0.16547679901123 2015 0.0877392515540123 2016 0.101931490004063 2017 0.0708981901407242 2018 0.103732906281948 2019 0.12788100540638 2020 0.0452405549585819 2021 -0.0710126981139183 2022 -0.125317960977554