Year Number 1996 -0.580390334129334 1998 -0.646357476711273 2000 -0.866051256656647 2002 -0.697901129722595 2003 -0.540637612342834 2004 -0.693985939025879 2005 -0.542147874832153 2006 -0.325426667928696 2007 -0.357663184404373 2008 -0.344882220029831 2009 -0.411506861448288 2010 -0.396869570016861 2011 -0.359688609838486 2012 -0.356279820203781 2013 -0.346435457468033 2014 -0.394620954990387 2015 -0.414675444364548 2016 -0.270433574914932 2017 -0.319819033145905 2018 -0.321435153484344 2019 -0.344945698976517 2020 -0.347207844257355 2021 -0.367464244365692 2022 -0.383247643709183