Year	1=low to 6=high
2005	2.9
2006	2.7
2007	2.7
2008	2.7
2009	2.7
2010	2.8
2011	2.9
2012	3
2013	3
2014	3
2015	3
2016	2.9
2017	2.8
2018	2.8
2019	2.8
2020	2.9
2021	2.9
2022	3
2023	3