Year 1=low to 6=high 2005 2.5 2006 2.5 2007 2.5 2008 2.5 2009 2.5 2010 2.5 2011 2 2012 2 2013 2 2014 2 2015 2 2016 2 2017 2 2018 2 2019 2 2020 1.5 2021 1.5 2022 1.5 2023 1