Year Number 1996 -0.361505150794983 1998 -0.17823214828968 2000 -0.178624525666237 2002 -0.171931698918343 2003 -0.087321013212204 2004 0.0682040601968765 2005 0.0187454242259264 2006 -0.11058596521616 2007 -0.231792405247688 2008 -0.274787336587906 2009 -0.229267567396164 2010 -0.237023547291756 2011 -0.269264370203018 2012 -0.281460791826248 2013 -0.327604949474335 2014 -0.302766591310501 2015 -0.34570524096489 2016 -0.259969264268875 2017 -0.195962429046631 2018 -0.18804033100605 2019 -0.180789098143578 2020 -0.322116583585739 2021 -0.257637172937393 2022 -0.157897114753723