Year 1=low to 6=high 2005 3.3991228070175445 2006 3.3829059829059824 2007 3.4088888888888884 2008 3.3959999999999995 2009 3.404761904761905 2010 3.3809523809523823 2011 3.3568376068376082 2012 3.329166666666667 2013 3.3312757201646086 2014 3.2982456140350873 2015 3.258771710526316 2016 3.2374426484018253 2017 3.2072072072072073 2018 3.2077625570776243 2019 3.173333328888889 2020 3.1529680365296806 2021 3.166666680555555 2022 3.1666666621621617 2023 3.175675675675676