Hi, Werner, good to see you around. (-:
Nevertheless, Else's post does give us a chance to look at the existing entries again with a fresh eye.
What leaps out at me is that 'attendance' isn't usually used as a countable noun with the indefinite article, so those entries seem misleading. Better examples might be, e.g.,
(The) attendance / turnout was good / poor / high / low / fair / average.
The event was well / poorly attended.
What was the attendance / turnout like?
How accurate are the attendance / turnout figures?
Also, 'large attendance' seems less idiomatic than several other possible adjectives.