29.9%: https://en.wikipedia.org/wiki/List_of_sovereign_states_and_d...

Among non-tiny countries, that's about 10th, between New Zealand and Australia. UAE has 87.9%! Qatar and Kuwait have a high percentage too. In terms of absolute numbers, USA has by far the most, over 50 million, and Germany and Saudi Arabia are next on 13 million.

In Japan the percentage is very low, but you can still have all the foreign food you want. Most foreigners in any country are doing other things than running restaurants, so it's pretty orthogonal.