Year	1=low to 6=high
2005	3
2006	2.9
2007	2.9
2008	2.8
2009	2.9
2010	3
2011	3
2012	3
2013	3.1
2014	3.1
2015	3.1
2016	3.1
2017	3.1
2018	3
2019	3.1
2020	3.3
2021	3.2
2022	3.2
2023	3.2