Year Number 1996 -1.17785394191742 1998 -1.08974099159241 2000 -1.39924204349518 2002 -0.724512279033661 2003 -1.19315183162689 2004 -1.51459443569183 2005 -1.2677013874054 2006 -0.908794343471527 2007 -0.863382518291473 2008 -0.749933898448944 2009 -0.969926595687866 2010 -0.929458737373352 2011 -0.998262107372284 2012 -0.817712664604187 2013 -0.736093640327454 2014 -0.943617463111877 2015 -1.03222346305847 2016 -0.947688162326813 2017 -0.642759621143341 2018 -0.538375675678253 2019 -0.551099121570587 2020 -0.667409420013428 2021 -0.707901835441589 2022 -0.918995440006256