Year	1=low to 6=high
2009	2.5
2010	2.7
2011	3
2012	3.1
2013	3.1
2014	3
2015	3
2016	3
2017	3.1
2018	3.1
2019	3.1
2020	3.1
2021	3.1
2022	3.1
2023	3.1