Year	1=low to 6=high
2005	3.638888888888889
2006	3.6300000000000003
2007	3.591954022988506
2008	3.5689655172413794
2009	3.5862068965517246
2010	3.563218390804598
2011	3.5
2012	3.422222222222223
2013	3.3655913978494625
2014	3.3555555555555556
2015	3.3833334444444447
2016	3.3448281609195396
2017	3.3448275862068977
2018	3.310344827586208
2019	3.3505748045977017
2020	3.3160919540229896
2021	3.2528736206896554
2022	3.1781610000000002
2023	3.1264368275862076