Year 1=low to 6=high 2005 3.4625 2006 3.4878048780487805 2007 3.573170731707317 2008 3.597560975609756 2009 3.5609756097560976 2010 3.524390243902439 2011 3.5238095238095237 2012 3.5595238095238093 2013 3.5697674418604652 2014 3.5853658536585367 2015 3.548780487804878 2016 3.513157894736842 2017 3.4473684210526314 2018 3.4078947368421053 2019 3.3846153846153846 2020 3.3815789473684212 2021 3.3421052631578947 2022 3.3205128205128207 2023 3.269230769230769