Year 1=low to 6=high 2005 2.75 2006 2.75 2007 2.75 2008 2.75 2009 2.75 2010 2.5 2011 2.5 2012 2.25 2013 2.25 2014 2.25 2015 2 2016 2 2017 2 2018 2 2019 2 2020 2.25 2021 2.25 2022 2.25 2023 2.25