"validatorCount" is number earning rewards on the first day of the "granularity"?

The "validatorCount" you return always gives the number of validators that did earn rewards on the first day of the "granularity" (e.g. "week/month"), correct?
When doing some calculations for periods where the number changed during the week, this led to some confusion at first.
https://api.rated.network/v1/eth/sets/SETID/proposals?fromDate=2024-06-03&toDate=2024-08-15&granularity=week&limit=100&offset=0
Internally, we are now resorting to an “"avg" number of reward- earning vals" if we are comparing different groups. Obviously this also has drawbacks like not being integer etc.