Year	1=extremely inefficient to 7=extremely efficient
2007	3.41176470588235
2008	3.253028600344
2009	3.2669693846
2010	3.6273944316
2011	3.5
2012	3.2
2013	3.1
2014	2.9
2015	3.21839097986619
2016	3.2
2017	3.6