Year Number 2005 -0.297008544206619 2006 -0.945403099060059 2007 -0.907076895236969 2008 -1.04394602775574 2009 -1.2219625711441 2010 -1.23685681819916 2011 -1.01274001598358 2012 -1.05861532688141 2013 -1.11494529247284 2014 -1.0034898519516 2015 -0.984151840209961 2016 -0.890493035316467 2017 -0.951291859149933 2018 -0.797005653381348 2019 -0.726854741573334 2020 -0.670987486839294 2021 -0.64892190694809 2022 -0.394462466239929