Year	1=low to 6=high
2011	2.8
2012	2.9
2013	2.9
2014	2.9
2015	2.9
2016	2.9
2017	2.9
2018	2.9
2019	2.8
2020	2.8
2021	2.9
2022	2.9
2023	2.9