This might be bordering on FOIG, but I don't really know of any practical way of doing it that isn't needlessly complex and time consuming.

If a priest (Mulciber) who spends a decent amount of time in the Sacred Cave were to look around, how many people would he notice regularly attend services or show up for prayers in the Ibrandul's temple? If possible, would he be able to tell the difference between followers from Upper and followers from Lower and roughly what percent of the faithful come from each area?

Has attendance in the Sacred Cave for services/sermons gone down with the recent violence in Lower, or has the danger inspired people to reach out for a deity and become more faithful?

And finally, based on attendance, quantity and quality of prayers, and tithing, could an attentive priest estimate what percent of followers are zealously (worship Ibrandul almost exclusively, will usually do what the priests tell them as long as it's in keeping with Ibranduls dogma), moderately (occasionally makes it to services, pays homage to a handful of deities), or loosely faithful (occasional offerings for self preservation)?

I'm working out a plan that will take this into account. Any information will be greatly appreciated.

The number of people who regularly visit the temple is pretty small. In addition to adventurers coming to raise their friends, you'd see groups of ragged Lower residents and the occasional Upper person. But by no means is it a huge following, even allowing for the small population that remains in the dangerous Lower district.

Thank you.