Year 1=low to 6=high 2005 3.388888888888889 2006 3.391891891891892 2007 3.391891891891892 2008 3.4054054054054053 2009 3.3684210526315788 2010 3.3552631578947367 2011 3.4210526315789473 2012 3.3684210526315788 2013 3.276315789473684 2014 3.1973684210526314 2015 3.1710526315789473 2016 3.1216216216216215 2017 3.1184210526315788 2018 3.1216216216216215 2019 3.1184210526315788 2020 3.1052631578947367 2021 3.108108108108108 2022 3.026315789473684 2023 3.026315789473684