Year	1=extremely inefficient to 7=extremely efficient
2007	3.47222222222222
2008	3.37316795810185
2009	4.0232258026
2010	4.4552554932
2011	4.1
2012	4
2013	3.3
2014	3
2015	3.09550339466817
2016	3.1
2017	2.4