That simply makes them one of today's lucky 10,000
https://xkcd.com/1053/
Lots of people are outside of the US
The spirit of the drawing applies everywhere. This 10000 figure looks made up anyway.
(hi from outside US :-))
The Hitchhiker's Guide to the Galaxy is British.
Also, I know it, it has been translated in my language (French), the movie made out to the theaters, and we even have a well known school named after it (42). So it is known even to non-English speakers.
It is, the question is it known or just there is a vague knowledge about it.