Year	1=low to 6=high
2005	3.022
2006	3.003921568627452
2007	3.0098039215686287
2008	3.0137254901960793
2009	3.0358490566037744
2010	3.0377358490566038
2011	3.050909090909092
2012	3.0140350877192987
2013	3.0017241379310353
2014	3.010344827586208
2015	3.001724137931035
2016	2.9947368421052643
2017	2.955172413793105
2018	2.9701754385964905
2019	2.9389830508474577
2020	2.9189655172413795
2021	2.90701754385965
2022	2.871186440677965
2023	2.8576271186440674