Below are some statistics from 1st May 2017.
Arendyll - 83,904 total players - 59,180 have a score of 1 or more - 24,724 (29.5%) have a score of zero.
Winyandor - 81,103 total players - 56,617 have a score of 1 or more - 24,486 (30.2%) have a score of zero.
It looks like at least 48K cities...