Year	1=extremely inefficient to 7=extremely efficient
2007	3.18041462050971
2008	3.27018810117141
2009	3.4831225943625
2010	3.60228870995882
2011	3.57647058823529
2012	3.62352941176471
2013	3.71875
2014	3.81875
2015	3.82994050136388
2016	3.81764705882353
2017	3.975