Participant numbers don't match Registered and Attended participants in meeting reports

[UBCEC]

What gives that the 'Participants' number in Usage Reports does not actually match actual the meeting participants numbers (or meeting participants that are unique). I actually just count how many names are in the Usage Report for each event and it's the difference between 23 names and the Participant number shows 31. The Participant number is sometimes even higher than the registration report number, so in the case above only 27 registered, how can there be 4 more people who attended? Yes I get that the host is not included in registration reports - but there is only one host for each meeting - so by that logic the number should only be off by 1 which is not the case.

(These are registered Meetings and not Webinars)