Year	1=low to 6=high
2005	2.5
2006	2.5
2007	2.5
2008	2.5
2009	2.5
2010	3
2011	2.5
2012	2.5
2013	3
2014	3.5
2015	3.5
2016	3.5
2017	3.5
2018	3.5
2019	3.5
2020	3.5
2021	3.5
2022	4
2023	4