User blog comment:IamJakuhoRaikoben/Chapter 413: The Book of E.N.D, Review./@comment-83.253.84.32-20141222153307/@comment-7418318-20141223153721

We know the inhabitants of Magnolia (60.000) and Fiore (17 million).

Even 10 % of Fiore's populance is still more than a million people. And Fiore is just one out of several countries on this continent.

So even if Fiore is exceptionally densly populated, it's still a very save bet to put 10 % of mankind at multiple millions, which is just too much for scattered stragglers living in caves, unless it's a Matrix-style Zyon or D&D-style Underdark.