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