Year 1=low to 6=high 2005 2.8684210526315788 2006 2.8947368421052633 2007 2.9210526315789473 2008 2.8947368421052633 2009 2.9 2010 2.9 2011 2.975 2012 2.925 2013 2.875 2014 2.9 2015 2.9 2016 2.95 2017 2.925 2018 2.9 2019 2.925 2020 2.9 2021 2.925 2022 2.95 2023 2.975