Table 5.

Error metrics of CO₂ emissions of USA

Fitting	NGM	SIGM	GMP	FGM	NGBM(1,1,k,c)	FAGM(1,1,$t^{\alpha }$)	FGBM
MAPE(%)	1.2262	1.2146	1.2037	1.1934	1.2262	1.3043	1.1320
MAE	63.4644	62.8228	62.315	62.1516	63.4644	67.8710	58.2463
Prediction	NGM	SIGM	GMP	FGM	NGBM(1,1,k,c)	FAGM(1,1,$t^{\alpha }$)	FGBM
MAPE(%)	1.8425	1.8391	1.7212	1.629	1.8425	1.5848	1.5805
MAE	91.7527	91.5873	85.8817	82.5036	91.7527	79.3186	79.0989