There were a lot of people standing on the floor, so my guestimate may have been a little off, but I figured :
About 25 people a row standing up on the floor
About 24 'rows'
Plus about 100 people in the balcony area.
Of course, what defines a 'row' is a bit tricky, so I could have overestimated a little. Regardless, it was an energetic gathering.