Year Number 1996 -0.309772878885269 1998 -0.154734894633293 2000 -0.288512378931046 2002 -0.165764808654785 2003 -0.349703222513199 2004 -0.22633421421051 2005 -0.500911414623261 2006 -0.315376073122025 2007 -0.305537134408951 2008 -0.252038717269897 2009 -0.216534748673439 2010 -0.172244891524315 2011 -0.211610183119774 2012 -0.263000935316086 2013 -0.287112712860107 2014 -0.284290075302124 2015 -0.325637251138687 2016 -0.299814790487289 2017 -0.369767844676971 2018 -0.291999518871307 2019 -0.335179150104523 2020 -0.270502895116806 2021 -0.327891737222672 2022 -0.291810005903244