Year 1=low to 6=high 2005 3.138888888888889 2006 3.1095890410958904 2007 3.1095890410958904 2008 3.1486486486486487 2009 3.1447368421052633 2010 3.151315789473684 2011 3.090909090909091 2012 3.0443037974683542 2013 3.00625 2014 2.973333333333333 2015 2.973333333333333 2016 2.9722222222222223 2017 2.952054794520548 2018 2.9652777777777777 2019 2.945945945945946 2020 2.9722222222222223 2021 3.0140845070422535 2022 3.0136986301369864 2023 3.041095890410959