Thanks for all the guesses - lots of interesting answers and thought gone into it
I am sure you are all on the edge of your seat to find out the answer?
To keep everyone happy I will tell you lots of different averages.
The mean number of members per caving club is 48
The median number of members per caving club is 22
The mode number of members per caving club is 7! (eight clubs have 7 members.)
As I was really thinking about the mean I am going to declare BabyHagrid the closest with their guess of 50!
Well done!
Although as a hitchhikers fan I am going to give PeteH a bonus point as 42 really is the answer to everything - and also one point for Standard Unit of Tom, for recognising the fact ;-)
This all leads me to the conclusion that the most average caving club in the UK is, in fact, the Eldon pothole club.
So not awesome at all, just average.
(Note this is the mean average caving club - I won't tell you the median/ mode most average caving clubs, as I am not members of them.........)
If you like numbers the mean caving club can be broken down further as
26 caving members, 6 non-caving members, 4 student members, 1 member under the age of 18, and 11 members who get their BCA membership as an individual or via another caving club = 48 members total.