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