I myself was disappointment by the figures but irrelevant of that Luton has an average of 136 passengers per flight (over a 12 month period) whilst Edinburgh has 94. Heathrow 154, Gatwick 145, Manchester 128, Glasgow 101. Unfortunately Stansted figures not yet out.
Luton has to be the most economical and thus the greener of airports or put another way is most efficient! And lets not forget has an excellent return in profits each subsequent year!