An Improved Nonhomogeneous Discrete Grey Model and Its Application

Table 5

The results of five grey models in natural gas demand of China (billion cubic meters).

Year	Raw data
		2003	35.0
		2004	41.5	46.18	46.29	45.74	35.15	40.69
		2005	49.3	52.07	52.19	51.73	45.04	50.32
		2016	58.6	58.70	58.83	58.40	54.65	59.78
2007	69.2	66.19	66.32	65.87	63.98	68.95
2008	80.3	74.61	74.77	74.24	73.03	77.85
2009	85.2	84.12	84.30	83.66	81.83	86.50
2010	94.8	94.84	95.02	94.24	90.36	94.92
2011	103.1	106.92	107.13	106.16	98.65	103.13
RMSE		3.29	3.30	3.23	5.06	1.17
MAPE (%)		4.19	4.26	4.15	7.53	1.39
2012	107.2	120.55	120.77	119.55	106.70	111.14
2013	119.3	135.91	136.15	134.62	114.52	118.98
RMSE		15.07	15.30	13.91	3.40	2.80
MAPE (%)		13.19	13.39	12.18	2.24	1.97