Year Number 1996 0.123815298080444 1998 0.370574235916138 2000 0.251223832368851 2002 0.345927983522415 2003 0.073229543864727 2004 0.0841383635997772 2005 -0.157522633671761 2006 -0.0679050013422966 2007 -0.0613481253385544 2008 -0.0977801457047462 2009 0.0622795186936855 2010 -0.116048209369183 2011 -0.028218861669302 2012 -0.179432675242424 2013 -0.141260921955109 2014 0.209008201956749 2015 0.377415180206299 2016 0.40072774887085 2017 0.380333244800568 2018 0.252037286758423 2019 0.290878117084503 2020 0.235460698604584 2021 0.307120054960251 2022 0.297832071781158