I don’t think a percentage by country would be a privacy issue.
Anyway, based on subjective forum observation, I’d say
- US (>50%)
- Germany (15~20%?)
- Canada (5~10%)
- France (4~9%)
- UK (3~8%)
- Australia (2~7%)
- the rest (<10%)
(The ordering of 3…6 is basically a wild guess. Could also be UK, FR, AU, CA)
Some hints about audience distribution are in the keyboard layout poll, although it’s missing UK, and of course layout does not directly indicate country.
here