Year Number 1996 0.854371190071106 1998 0.50556892156601 2000 -0.250100612640381 2002 0.14875116944313 2003 0.478074342012405 2004 0.664763033390045 2005 0.625976085662842 2006 0.782249569892883 2007 1.01876068115234 2008 1.20101487636566 2009 0.929570853710175 2010 0.846940040588379 2011 0.911657512187958 2012 0.978104293346405 2013 0.958809971809387 2014 0.608740627765656 2015 0.725260257720947 2016 0.699528992176056 2017 0.621905207633972 2018 0.684950053691864 2019 0.528806626796722 2020 0.512376427650452 2021 0.518684864044189 2022 0.556306064128876