I thought I had answered this already, but that must have been on another forum.
Anyway, and additionally, it's the "US", not "USA". It's an abbreviation for "Universal System", which of course means it never even achieved global acceptance.
It didn't "predate the f-stop numbers", but instead was one of several concurrent systems in use. Among them were F-numbers, the Stolze system, US, and several others including arbitrary numbers and the diameter in mm.
Apart from that, I agree with Murray: I'm sure those stops are in US.
And his table is correct, too!