Year Number 2004 0.993218183517456 2005 1.37641596794128 2006 1.30346059799194 2007 1.28656852245331 2008 1.3163959980011 2009 1.12155425548553 2010 1.10084736347198 2011 1.28573775291443 2012 1.26388156414032 2013 1.31222629547119 2014 1.16456782817841 2015 1.21023952960968 2016 1.26075851917267 2017 1.31384432315826 2018 1.33727550506592 2019 1.33566856384277 2020 1.37149739265442 2021 1.4315470457077 2022 1.47468435764313