Using a Novel Grey System Model to Forecast Natural Gas Consumption in China

Table 2

Fitted values and MAPE of different models.

Year	Actual value	Model (40)	GM(1, 1)	Reference [5]	WLSGM(1, 1)	DGM(1, 1)
1990	45.41	44.71	45.41	44.07	45.41	45.41
1991	47.56	47.93	42.18	46.40	47.14	42.26
1992	50.58	50.52	46.32	49.48	49.19	46.40
1993	51.85	53.55	50.85	53.16	51.62	50.94
1994	56.25	57.09	55.83	57.49	54.50	55.93
1995	58.63	61.22	61.30	60.83	57.91	61.41
1996	59.94	66.04	67.31	60.62	61.97	67.42
1997	75.43	71.68	73.90	77.07	66.77	74.02
1998	82.45	78.27	81.14	82.15	72.48	81.27
1999	93.40	85.96	89.08	90.44	79.24	89.23
2000	100.67	94.94	97.81	98.72	87.26	97.96
2001	103.63	105.43	107.39	107.7	96.77	107.55
2002	111.71	117.68	117.91	116.93	108.05	118.09
2003	128.19	131.99	129.45	123.54	121.42	129.65
2004	151.04	148.71	142.13	146.05	137.29	142.34
MAPE		3.7	4.82	2.6	5.88	4.76
2005	166.29	168.24	156.06	164.21	156.11	156.28
2006	185.83	191.05	171.34	179.51	178.42	171.58
MAPE		1.99	3.48	2.3	5.06	3.42