Table 7.

Grey relational degree of each city.

City	${{\mathit{Q}}_{\mathit{i}}}^{\mathbf{+}}$	${{\mathit{Q}}_{\mathit{i}}}^{\mathbf{-}}$	City	${{\mathit{Q}}_{\mathit{i}}}^{\mathbf{+}}$	${{\mathit{Q}}_{\mathit{i}}}^{\mathbf{-}}$
Heifei	1.000	0.000	Lu’an	0.135	0.779
Huaibei	0.053	0.944	Ma’anshan	0.123	0.730
Bozhou	0.099	0.894	Wuhu	0.333	0.365
Suzhou	0.063	0.918	Xuancheng	0.226	0.662
Bengbu	0.098	0.768	Tongling	0.148	0.741
Fuyang	0.101	0.828	Chizhou	0.258	0.716
Huainan	0.000	1.000	Anqing	0.206	0.624
Chuzhou	0.167	0.683	Huangshan	0.370	0.648