Year Number 1996 -0.656428635120392 1998 -0.907693862915039 2000 -1.06835269927979 2002 -1.18801403045654 2003 -1.26386892795563 2004 -1.08735477924347 2005 -1.25050592422485 2006 -1.12698328495026 2007 -1.30544221401215 2008 -1.39361536502838 2009 -1.42558062076569 2010 -1.16552352905273 2011 -1.24479079246521 2012 -1.32344126701355 2013 -1.16693091392517 2014 -1.28224718570709 2015 -1.24134790897369 2016 -1.35445654392242 2017 -1.12843835353851 2018 -1.17969214916229 2019 -1.10573601722717 2020 -1.00722682476044 2021 -1.03241419792175 2022 -0.943087220191956