GregF:
018 in 1995 was cranking around 60k per day - it was when it was free. Day time reps were running ~1000 calls / day - nice simple requests. I found I'd be way under that doing nights - the callers were often on a bit of a hunt, and needed more time.
I did a lot of 4:30pm to Midnight, or midnight to 7am shifts. I was way down in the 400-600 range, less on the Midnight shift.
We also ran 111, that was interesting times at night.
It was good money for a student - almost a double win, as it kept me out of the pub spending it!
Heh, those were the days! I think the whole message centre took around 22 000-24 000 calls on a typical weekday. Weekends and afterhours were a lot less (similar to your situation). Even 018 wouldn't be that busy now.