Year	1=extremely inefficient to 7=extremely efficient
2007	3.11113310564741
2008	3.11983206516395
2009	3.44164033252593
2010	3.80216060723929
2011	3.67333333333333
2012	3.6125
2013	3.55294117647059
2014	3.47575757575758
2015	3.47140992558898
2016	3.47878787878788
2017	3.565625