Year 1=low to 6=high 2005 4 2006 4 2007 4 2008 4 2009 3.5 2010 3 2011 3 2012 3 2013 3.5 2014 3.5 2015 3.5 2016 3 2017 3.5 2018 3.5 2019 4 2020 4 2021 4 2022 4 2023 4