Year	1=low to 6=high
2005	3.1527777777777777
2006	3.0675675675675675
2007	3.108108108108108
2008	3.081081081081081
2009	3.0526315789473686
2010	3
2011	3.026315789473684
2012	3.039473684210526
2013	3.0526315789473686
2014	3.0657894736842106
2015	3.0657894736842106
2016	3.0405405405405403
2017	2.9342105263157894
2018	2.9324324324324325
2019	2.8552631578947367
2020	2.8684210526315788
2021	2.918918918918919
2022	2.9210526315789473
2023	2.9078947368421053