Year	1=low to 6=high
2005	3.6
2006	3.6
2007	3.7
2008	3.7
2009	3.6
2010	3.6
2011	3.3
2012	2.9
2013	2.9
2014	3.1
2015	3.2
2016	3.3
2017	3.3
2018	3.3
2019	3.3
2020	3.3
2021	3.3
2022	3.3
2023	3.3