Year 1=low to 6=high 2005 2.5 2006 2.5 2007 2.5 2008 2 2009 2 2010 2 2011 2 2012 2 2013 2.5 2014 2.5 2015 2.5 2016 2.5 2017 2.5 2018 3 2019 3 2020 3 2021 3 2022 3 2023 3