Year	1=low to 6=high
2005	3.0793650793650795
2006	3.1
2007	3.123076923076923
2008	3.0538461538461537
2009	3.037313432835821
2010	3.029850746268657
2011	3.036231884057971
2012	2.971830985915493
2013	2.9444444444444446
2014	2.9444444444444446
2015	2.9027777777777777
2016	2.8450704225352115
2017	2.826388888888889
2018	2.8380281690140845
2019	2.8219178082191783
2020	2.787671232876712
2021	2.7708333333333335
2022	2.777027027027027
2023	2.804054054054054