Container Throughput Forecasting of Tianjin-Hebei Port Group Based on Grey Combination Model

Table 6

Comparison of the two data between the combination model and the original data.

Year	Tian. r = 1 norm.	Tang. r = 0.2 norm.	Qin. r = 0.2 norm.	Huang. r = 0.2 norm.	Total original data norm.	BPNN training results	Trained data antinorm. (unit:10,000 TEU)	Error
2012	0.01	0.01	0.01	0.01	0.01	0.019	1320.00	0.00%
2013	0.13	0.06	0.10	0.15	0.11	0.102	1426.34	−0.67%
2014	0.19	0.12	0.21	0.27	0.24	0.242	1605.71	1.05%
2015	0.25	0.19	0.31	0.37	0.30	0.32	1705.65	2.56%
2016	0.31	0.28	0.40	0.47	0.38	0.389	1794.05	2.05%
2017	0.37	0.38	0.48	0.56	0.48	0.426	1841.45	−2.10%
2018	0.43	0.50	0.55	0.65	0.60	0.601	2065.67	1.91%
2019	0.50	0.64	0.61	0.73	0.70	0.658	2138.70	−0.20%
2020	0.56	0.80	0.67	0.81	0.82	0.773	2286.04	0.18%