The numbers show how many analyses need to be calculated before your calculation is started. It is essentially an indicator of the estimated waiting time.
Background: If there are several parallel analysis requests (e.g., by other users), they are put into a queue. The number shows your position in the queue.
Please note that there are several different factors that influence the loading time of an analysis, for example:
the chosen time period
the number of dimensions and metrics
type and number of the filters used