Year Number 2003 1.16978526115417 2004 1.27009546756744 2005 1.38492727279663 2006 1.34965407848358 2007 1.34201574325562 2008 1.33847212791443 2009 1.4026106595993 2010 1.42273163795471 2011 1.30248832702637 2012 1.29035115242004 2013 1.28392601013184 2014 1.29932725429535 2015 1.36598539352417 2016 1.38275027275085 2017 1.21373701095581 2018 1.39100873470306 2019 1.17167043685913 2020 1.21819925308228 2021 1.26768326759338 2022 1.18453228473663