Year % 2000 1.188822630408374 2001 1.1495127337846485 2002 1.090672400287862 2003 1.038874109008699 2004 1.0049583101362571 2005 0.9660762020165498 2006 0.9104260100670215 2007 0.8918252124681694 2008 0.8727808057624717 2009 0.845509516290525 2010 0.807492126938746 2011 0.7769212738899361 2012 0.7470763830003603 2013 0.7296263857966035 2014 0.7075924825715817 2015 0.6851113148814851 2016 0.6696500820109353 2017 0.6541824948761097 2018 0.6409571004367733 2019 0.6284298876924831 2020 0.6020638104336151