

Oh, I was thinking they meant 65-75 people before the pendulum (the second counter on the grandfather clock?) swung back, so 65-75 people per second. I didn’t think so deeply about the maths behind it, just accepted it as a possible meaning. But I’ll do it now.
UPDATE: Checks out for 2-3 years, but something is telling me there was enough time for even more years to fit between 1939 and 1945.
UPDATE: Unless you consider “swung back” as 2 seconds, because then it’s even possible.
Oh, yes you’re right - I’m not a native speaker and I think we phrase it slightly differently, and I took that literally. Thanks for the explanation!