Table 2.

Mean fitting and predicting accuracy test results of typical and proposed GM(1,1) models: Eqs. (20) and (21).

	Mean fitting performance						Mean predicting performance
	MAE	MAPE	MSE	WMAE	WMAPE	WMSE	MAE	MAPE	MSE
Typical GM(1,1)	0.030710	0.952136	0.001492	0.047095	1.296930	0.002606	0.799794	2.610734	1.144524
Proposed GM(1,1)	0.001082	0.044535	0.000002	0.001175	0.041488	0.000039	0.086598	0.245112	0.015485