Year	1=extremely inefficient to 7=extremely efficient
2007	4.84848484848485
2008	4.5819187221754
2009	3.9678777846
2010	4.2975293131
2011	4.7
2012	4.5
2013	4.4
2014	4.4
2015	4.34012914780648
2016	4.3
2017	4.7