Fig. 7

The comparison of average daily increments between Sichuan and the other 6 provinces. *One unit of the abscissa was a week (7 days). It set the day that the first cases reported in each province as the starting point. During the two weeks before the Hubei lockdown, the top destination of Hubei’s emigration population was Henan Province. Sichuan Province ranked seventh. Taking the migration from Hubei at this stage as a possible high-risk factor, this chart selected the provinces that rank close to Sichuan Province (rank 4 to 10) for comparison. The peak time in Sichuan Province was earlier (occured in the second week according to the weekly analysis, ranked the first in common), and the peak was lower (26.7 cases average daily increment in that week, only higher than Shaanxi). The fluctuation after the eighth week of each province mainly came from imported cases abroad. The data go up to April 21 in this figure