The formula for population density is Dp= N/A, where Dp is the population density, N is the total population, and A is the land area covered by the population. For human populations, A is typically expressed as square miles or square kilometers.
The population density of a country or city or other place is a number showing how crowded that place is. ... For example, France has a population of 60,561,200, and an area of 551,695 square kilometres, so its population density is about 109.8 persons per square kilometre.
Mainly the Ocean between the countrys, they are far away. You could of been on a boat for over 1 month and had to use a pot as a toilet. People also died on the way over. They died because the ships sometimes did not have enough food or water.