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