Year Number 1996 1.4541187286377 1998 1.29750728607178 2000 1.54021811485291 2002 1.47916531562805 2003 1.16710090637207 2004 1.30585932731628 2005 1.41652750968933 2006 1.41256189346313 2007 1.34514999389648 2008 1.31798684597015 2009 1.32123482227325 2010 1.44162690639496 2011 1.47659265995026 2012 1.54359126091003 2013 1.49895906448364 2014 1.44105923175812 2015 1.1831693649292 2016 1.02332496643066 2017 1.00147747993469 2018 0.958148717880249 2019 0.979157269001007 2020 1.10673403739929 2021 0.956733345985413 2022 0.968280136585236