Year Number 1996 -0.986241638660431 1998 -1.12488889694214 2000 -1.12596011161804 2002 -1.38355255126953 2003 -1.18086850643158 2004 -1.231241106987 2005 -1.22173345088959 2006 -1.19514667987823 2007 -1.0676943063736 2008 -0.988219559192657 2009 -0.978557884693146 2010 -0.952039062976837 2011 -0.903721451759338 2012 -0.995809435844421 2013 -0.904471814632416 2014 -0.766805112361908 2015 -0.700742721557617 2016 -0.545297205448151 2017 -0.624594211578369 2018 -0.758381545543671 2019 -0.730480670928955 2020 -0.751222908496857 2021 -0.796347439289093 2022 -0.762097477912903