Community size per month as a measure

Is there currently a way of getting a value for "community size", i.e. the total number of people who execute any action in relation to a repository (except for WatchEvent) for a given month? I mean not just ordering by this value, but actually getting monthly statistics for it.

No source file, test, or entry point is named. Start by reading the repository's existing GitHub activity analysis code, then determine how monthly repository activity is represented; done means exposing monthly community-size values that exclude WatchEvent, rather than only ordering by the measure.

Written by the indexing model from the issue text.