I'm working on gathering information about past Meetups for annual reports. 2017 annual report had an attendee count included in the numbers reported and I think that's a really nice number to have and compare.

Currently, there's no way to get that number from reports tool. Meetup.com do have their own Pro dashboard from where you can get these numbers out surely, but it would be neat to have the attendance count (attended members) included on our reports as Meetup.com API do return that information.