Year	1=extremely inefficient to 7=extremely efficient
2007	3.32142857142857
2008	3.5541696986711
2009	3.9168211895
2010	3.9714544
2011	3.9
2012	4.1
2013	4
2014	3.9
2015	3.80135560972842
2016	3.8
2017	3.7