Year Number 2009 1.02569842338562 2010 1.01214551925659 2011 1.0010347366333 2012 0.996137678623199 2013 0.938787341117859 2014 0.916511118412018 2015 0.843033373355865 2016 0.815052211284637 2017 0.810150265693665 2018 0.808106005191803 2019 0.786948084831238 2020 0.766806840896606 2021 0.748871743679047 2022 0.756873250007629