I guess what Ripper is getting at, is that attendances or ground capacities on average 40+ years ago weren't the same as these days.
It wasn't very common for grounds to regularly sell out like it is today.
Fair enough the ground capacities part was wrong but it's only been in the last ~20 years that stadiums regularly sell out.
What was Newcastle's average attendace in the 50's, 60's or 70's?
So you see my point. Average attendances are far more these days.