Range, mean, SD and inter-correlation of COVID-19 spread days, cumulative COVID-19 cases, GDP, population densities and spatial distances
| Variable | N | Range | Mean (SD) | 2 | 3 | 4 | 5 |
| days | 30 | 42–53 | 44.97 (1.88) | −0.49** | −0.48** | 0.55** | −0.40* |
| Cases (n) | 30 | 1–1322 | 412.27 (395.56) | 0.69** | −0.53** | 0.13 | |
| GDP | 30 | 0.12–7.72 | 2.25 (1.94) | −0.42* | 0.26 | ||
| Distance | 30 | 3.02–28.90 | 10.68 (6.26) | −0.22 | |||
| Pop. density | 30 | 0.03–38.48 | 4.68 (7.22) |
Days: number of days from the first COVID-19 case in China to the date when a COVID-19 case was detected in a destination province; cases (n): cumulative COVID cases; GDP: 2019 GDP (trillion RMB Yuan); distance: spatial distance (100 km) between a destination province and Hubei; and pop. density: population density (100 persons/km2). See detailed description in the text.
*p<0.05, **p<0.01.
GDP, gross domestic product.