Table 2.

Spearman correlation coefficients of population density, economy, geographic location (latitude and longitude), and incidence from 2013 to 2022.

Correlation
			Incidence	Population density	economy	Longitude	Latitude
Spearman Rho	Incidence	Correlation coefficient	1	0.414**	0.421**	0.13	0.403**
		Significance (two-tailed)		0	0	0.08	0
		Case	183	183	126	183	183
	Population density	Correlation coefficient	0.414**	1	0.739**	0.370**	0.282**
		Significance (two-tailed)	0		0	0	0
		case	183	183	126	183	183
	Economy	Correlation coefficient	0.421**	0.739**	1	0.236**	0.089
		Significance (two-tailed)	0	0		0.008	0.324
		Case	126	126	126	126	126
	Longitude	Correlation coefficient	0.13	0.370**	0.236**	1	0.265**
		Significance (two-tailed)	0.08	0	0.008		0
		case	183	183	126	183	183
	Latitude	Correlation coefficient	0.403**	0.282**	0.089	0.265**	1
		Significance (two-tailed)	0	0	0.324	0
		Case	183	183	126	183	183

**At the 0.01 level (two-tailed), the correlation is significant. The population density and economic data were obtained from the 2023 Hainan Statistical Yearbook. It should be noted that economic data was only updated for the years 2015 and 2017–2022. The longitude and latitude data for each city and county were sourced from Tianditu (https://map.tianditu.gov.cn/). Economic indicators come from local fiscal revenue and expenditure in various cities and counties. Local fiscal revenue includes local general budget revenue and expenditure and fund revenue. Longitude and latitude are the coordinates of the icons in each city and county.