Year Number 2003 1.16978526115417 2004 1.1569436788559 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 0.801865816116333 2015 0.821486234664917 2016 0.846926331520081 2017 0.855434954166412 2018 0.998590290546417 2019 1.12423300743103 2020 1.16373264789581 2021 1.13891088962555 2022 1.11602663993835