(It's not US-only, by any means, and info about Ireland is not something we ignore because "nobody cares about that". But it's reasonable to point out that this is not data from the conditions that most people here assume by default.)
Or perhaps they do!
Now that you ask, I'm also not sure of the source of that statistic. I'm pretty sure dang knows, but he may not be the source of the information. It may have just been someone's informed guess, or uninformed guess for that matter.
I do know that there are lots of people not from the US here, and that you shouldn't assume, for example, that English is someone's first language. Also shouldn't assume US vs England even for native English speakers (so don't attempt to "correct" British spelling).