According to Celestia, the total population of Equestria was around two hundred million, and that included all the species that lived here. Ponies, mules, zebra, cows and buffalo, the occasional griffon, and so on... The human population would eclipse that thirty-five to one, and that wasn't even counting pets and livestock, and whatever other animals they hoped to rescue from Earth. Even counting in all the rest of the known sapient species in this entire world, the total came up to slightly under a billion souls, total. 