Year 1=low to 6=high 2005 3.277272727272727 2006 3.2284722222222215 2007 3.2295454545454545 2008 3.2818181818181817 2009 3.3318181818181816 2010 3.3515151515151516 2011 3.2807692307692307 2012 3.235714285714286 2013 3.2022222222222223 2014 3.203333333333333 2015 3.1838891111111116 2016 3.136904285714286 2017 3.119047619047619 2018 3.1214285714285714 2019 3.102976142857144 2020 3.0940476190476183 2021 3.060118928571429 2022 3.0511903571428576 2023 3.034523714285714