I would agree with that, at least for this site. I wouldn't be surprised if the ratio was 1 to 10, since tech skews it significantly. For example, I work in tech in the US, and the only American I've spoken to today was my summer intern, and - oh hold up, I just typed that and realized she's from Canada. OK, I've been in work meetings all day and I have not spoken to a "US American" during that time. I suspect that other sites, particularly some subreddits, are mostly American, though.