Year 1=low to 6=high 2005 2.981081081081081 2006 2.9702702702702704 2007 2.9702702702702704 2008 2.948648648648649 2009 2.9631578947368418 2010 2.9657894736842105 2011 2.9815789473684204 2012 2.9307692307692306 2013 2.925641025641027 2014 2.960526315789473 2015 2.9631578947368418 2016 2.9684210526315793 2017 2.9282051282051285 2018 2.95 2019 2.9230769230769242 2020 2.9128205128205136 2021 2.9051282051282055 2022 2.8923076923076922 2023 2.882051282051282