Year	1=low to 6=high
2005	3.7
2006	3.7
2007	3.7
2008	3.7
2009	3.7
2010	3.7
2011	3.7
2012	3.7
2013	3.6
2014	3.5
2015	3.5
2016	3.5
2017	3.5
2018	3.5
2019	3.6
2020	3.6
2021	3.5
2022	3.5
2023	3.5