Year 1=low to 6=high 2005 3.36 2006 3.3137254901960786 2007 3.343137254901961 2008 3.3823529411764706 2009 3.349056603773585 2010 3.3679245283018866 2011 3.3363636363636364 2012 3.219298245614035 2013 3.163793103448276 2014 3.1120689655172415 2015 3.0775862068965516 2016 3.043859649122807 2017 3.043103448275862 2018 3.043859649122807 2019 3.0508474576271185 2020 3.0344827586206895 2021 3.017543859649123 2022 2.9237288135593222 2023 2.9237288135593222