Year	1=extremely inefficient to 7=extremely efficient
2007	4.36111111111111
2008	4.34115286153846
2009	4.3981500282
2010	4.6271204634
2011	4.7
2012	4.8
2013	5
2014	5.1
2015	5.03418133335729
2016	5
2017	5