Year Number 1996 -0.128497436642647 1998 0.0239137783646584 2000 0.0260655991733074 2002 -0.207287535071373 2003 -0.14708548784256 2004 -0.167148128151894 2005 -0.118025802075863 2006 -0.162207126617432 2007 -0.228115558624268 2008 -0.323701977729797 2009 -0.392095685005188 2010 -0.143460005521774 2011 -0.142604574561119 2012 -0.24008908867836 2013 -0.3071448802948 2014 -0.255771666765213 2015 -0.401139050722122 2016 -0.482714980840683 2017 -0.460668236017227 2018 -0.673814237117767 2019 -0.809006750583649 2020 -1.20486307144165 2021 -1.31169736385345 2022 -1.45865571498871