Year Number 1996 0.161260232329369 1998 0.0642771571874619 2000 0.159529581665993 2002 0.338851630687714 2003 0.244941875338554 2004 0.21113657951355 2005 0.158469423651695 2006 0.177752673625946 2007 0.131876915693283 2008 -0.000771665305364877 2009 -0.101635470986366 2010 -0.118414133787155 2011 -0.117064774036407 2012 -0.114084355533123 2013 -0.265588670969009 2014 -0.149271368980408 2015 0.0317260250449181 2016 0.107241459190845 2017 0.0267022158950567 2018 -0.000408620457164943 2019 0.0395575873553753 2020 -0.00758194550871849 2021 0.0178692117333412 2022 -0.0569253154098988