Year 1=low to 6=high 2005 3.272727272727272 2006 3.2055555555555553 2007 3.2121212121212124 2008 3.2363636363636363 2009 3.3030303030303028 2010 3.303030303030303 2011 3.256410256410256 2012 3.2261904761904754 2013 3.21111111111111 2014 3.222221555555556 2015 3.188888222222222 2016 3.190475 2017 3.154761904761903 2018 3.154761904761903 2019 3.1071427857142866 2020 3.095238095238094 2021 3.0714286428571427 2022 3.059523857142857 2023 3.0595237857142856