Table 9.

Quarterly environmental efficiency of freight subsystem with the IEBM model during 2018–2020

Airlines	2018				2019				2020
	Q1	Q2	Q3	Q4	Q1	Q2	Q3	Q4	Q1	Q2	Q3	Q4
Aeroflot	0.917	0.927	1.000	0.886	0.875	0.914	1.000	0.908	0.763	0.618	1.000	0.882
Air China	0.945	1.000	0.975	1.000	0.901	1.000	1.000	0.939	0.804	1.000	1.000	0.987
All Nippon	0.946	1.000	0.973	0.988	0.865	0.955	1.000	0.991	0.866	0.852	0.896	1.000
Cathay Pacific	0.996	1.000	1.000	0.999	1.000	0.998	0.988	1.000	1.000	1.000	1.000	0.998
China Airlines	0.769	0.879	0.916	0.883	0.953	0.917	0.932	0.881	1.000	0.917	0.901	0.910
China Eastern	0.992	1.000	1.000	0.883	0.974	0.978	1.000	0.983	0.780	0.702	0.881	0.849
China Southern	0.970	0.927	1.000	0.892	0.969	0.922	1.000	1.000	0.971	0.770	1.000	0.820
Eva Air	0.987	0.922	0.955	0.922	1.000	1.000	0.908	0.842	0.942	0.905	0.885	1.000
Hainan	0.996	1.000	1.000	0.968	1.000	1.000	0.990	0.887	0.912	0.857	0.930	1.000
Juneyao	0.994	0.993	1.000	0.947	0.973	0.962	0.957	0.957	0.851	0.877	1.000	1.000
KLM Royal Dutch	1.000	0.929	0.972	1.000	0.976	0.821	0.930	1.000	0.848	1.000	0.813	0.942
Lufthansa	0.959	0.929	1.000	1.000	0.883	0.916	0.898	0.983	0.842	0.791	0.814	0.847
Singapore	0.995	0.968	0.974	1.000	0.972	0.949	0.959	1.000	0.821	0.826	0.840	0.977
Spring	0.947	0.951	0.965	0.896	0.980	0.971	1.000	0.918	0.822	0.902	1.000	0.970
Min	0.769	0.879	0.916	0.883	0.865	0.821	0.898	0.842	0.763	0.618	0.813	0.820
Mean	0.958	0.959	0.981	0.947	0.952	0.950	0.969	0.949	0.873	0.858	0.926	0.942
Std	0.058	0.039	0.024	0.049	0.047	0.048	0.036	0.052	0.076	0.108	0.071	0.064