Population data is obtained from REST Countries and some gaps are filled from Wikipedia.

The obtained data has detailed information on provinces/states for the following countries: Australia, Canada and China. The individual numbers from provinces are summed up per country to show an overall number.

The World entry is obtained by summing up the available data from all countries. Similarly, the world population is computed as the sum of all populations for which we have data.

If enabled, Smoothing is applied as a 7-day average centered on the indicated date. That means the three days before and after the date are included in the calculation. For the first and most recent three days of the observation period this cannot be computed, so those days are not shown on the graph when smoothing is applied.