Year	1=extremely inefficient to 7=extremely efficient
2007	3.1938443786463
2008	3.1830320487022
2009	3.43890972608333
2010	3.6856365276
2011	3.53
2012	3.46842105263158
2013	3.47368421052632
2014	3.41111111111111
2015	3.32259889054188
2016	3.32777777777778
2017	3.31875