Analyzing the Relationship between the PM_2.5 Concentration and the Gini Coefficient Using the Grey Model

Table 7

Fitting results of the PM_2.5 concentrations in South China.

Year	Guangdong			Guangxi			Hainan
	Gini coefficient	PM2.5	Result	Gini coefficient	PM2.5	Result	Gini coefficient	PM2.5	Result
2006	0.410	41.9	41.9	0.435	45.8	45.8	0.375	21.1	21.1
2007	0.408	43.1	38.4	0.451	45.1	44.3	0.383	24.7	19.3
2008	0.407	43.0	38.1	0.449	45.3	45.2	0.378	23.9	19.1
2009	0.405	41.9	37.8	0.454	39.1	45.4	0.380	17.9	19.1
2010	0.438	38.3	41.1	0.430	42.5	44.2	0.383	16.0	19.3
2011	0.426	43.3	43.3	0.433	49.0	42.9	0.424	24.5	21.8
2012	0.409	36.9	40.2	0.399	47.0	41.1	0.367	15.8	18.8
2013	0.437	36.0	41.4	0.403	40.5	39.4	0.372	20.7	18.6
2014	0.368	35.6	37.3	0.393	40.3	39.1	0.356	16.6	17.7
2015	0.375	30.7	31.5	0.382	35.4	38.0	0.367	15.9	18.2
2016	0.372	28.6	31.9	0.405	32.2	38.6	0.365	15.9	18.2
MAPE	7.48%			7.25%			13.20%
2017	0.369		31.4	0.403		39.8	0.364		18.1
2018	0.366		30.9	0.400		39.5	0.364		18.1
2019	0.363		30.4	0.398		39.2	0.363		18.1