Year 1=low to 6=high 2005 4 2006 4 2007 4 2008 4 2009 4 2010 4 2011 4 2012 4.5 2013 4.5 2014 4.5 2015 3.5 2016 3 2017 3 2018 3 2019 3 2020 3 2021 3 2022 2.5 2023 3