Year	1=low to 6=high
2011	2.7
2012	2.6
2013	2.6
2014	2.6
2015	2.6
2016	2.6
2017	2.6
2018	2.6
2019	2.6
2020	2.6
2021	2.7
2022	2.7
2023	2.8