Year	1=low to 6=high
2005	3.1013157894736842
2006	3.0717948717948733
2007	3.081333333333334
2008	3.084000000000001
2009	3.103896103896105
2010	3.1090909090909093
2011	3.1128205128205133
2012	3.08625
2013	3.075308641975308
2014	3.0618421052631577
2015	3.0565789473684193
2016	3.042465753424656
2017	3.012162162162161
2018	3.0260273972602727
2019	3.0066666666666664
2020	2.986301369863013
2021	2.9847222222222225
2022	2.9513513513513514
2023	2.943243243243243