Year	1=low to 6=high
2005	3.9
2006	3.9
2007	4
2008	4
2009	4
2010	4
2011	4
2012	4
2013	4.1
2014	4
2015	4
2016	3.8
2017	3.9
2018	4
2019	4
2020	4.1
2021	4.1
2022	4
2023	4