I quoted your use of "not unexpected" because it suggests that you have some expectation. I would call the the basis for that expectation part of a presumption that you know.
Yeah, i can see how it could be interpreted like that. I didn't have any strong expectation of how it should be. Merely a number of guesses as where that number could end up. To me it seems reasonable that the number would end up somewhere between half of the local percentage and 1.5x of the us percentage (assuming foreigners are not statistically significant), which would put it somewhere between 2.5% and 25%. To me numbers outside of that would be unexpected and surprising.
Interestingly, the 30% number seems to indicate that twitter actually does pretty good user-wise.
Your own statistics reference indicates that 36% of the Bay Area population is foreign born, and 16% do not have US citizenship, so you cannot assume that "foreigners are not statistically significant."
Interestingly, the 30% number seems to indicate that twitter actually does pretty good user-wise.