Year Number 1996 -1.16629016399384 1998 -1.24434244632721 2000 -1.11005222797394 2002 -1.04466021060944 2003 -1.07671809196472 2004 -0.802059054374695 2005 -0.715685963630676 2006 -0.916875541210175 2007 -0.984122395515442 2008 -0.979712247848511 2009 -1.03841888904572 2010 -1.02233076095581 2011 -1.00412118434906 2012 -0.906026601791382 2013 -0.893353223800659 2014 -0.813357710838318 2015 -0.847575545310974 2016 -0.861592352390289 2017 -0.902944028377533 2018 -0.995128452777863 2019 -1.05331110954285 2020 -1.0879522562027 2021 -1.00932395458221 2022 -1.00387418270111