We know that by definition, "Population Density" is a measurement of population per unit area. This is usually calculated by dividing the total population by the total area. Population density is expressed as number of people per squared miles.
Thus, for our question, the term that should come in the blank is "Population Densities".
Hence, the complete answer will be:
Bangladesh has 2596 persons per square mile, while the united states has 780 persons per square mile and canada has 9 persons per square mile. these statistics compare the Population Densities of these countries.