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