Year 1=low to 6=high 2005 3.1125 2006 3.1341463414634148 2007 3.1707317073170733 2008 3.1219512195121952 2009 3.1341463414634148 2010 3.1219512195121952 2011 3.1547619047619047 2012 3.0714285714285716 2013 3.046511627906977 2014 3.048780487804878 2015 2.9878048780487805 2016 2.9210526315789473 2017 2.9078947368421053 2018 2.9078947368421053 2019 2.8974358974358974 2020 2.8684210526315788 2021 2.8157894736842106 2022 2.8461538461538463 2023 2.8846153846153846