Year	1=low to 6=high
2005	3.189189189189189
2006	3.2162162162162162
2007	3.2567567567567566
2008	3.2567567567567566
2009	3.276315789473684
2010	3.3157894736842106
2011	3.4342105263157894
2012	3.4615384615384617
2013	3.4871794871794872
2014	3.526315789473684
2015	3.526315789473684
2016	3.5526315789473686
2017	3.5384615384615383
2018	3.5921052631578947
2019	3.5256410256410255
2020	3.5384615384615383
2021	3.5384615384615383
2022	3.5641025641025643
2023	3.58974358974359