GPWv4: Gridded Population of the World Version 4, UN-Adjusted Population Count (CIESIN/GPWv4/unwpp-adjusted-population-count)

The Gridded Population of World Version 4 (GPWv4) models the distribution
of global human population for the years 2000, 2005, 2010, 2015, and 2020
on 30 arc-second (approximately 1km) grid cells. Population is distributed
to cells using proportional allocation of population from census and
administrative units. Population input data are collected at the most
detailed spatial resolution available from the results of the 2010 round of
censuses, which occurred between 2005 and 2014. The input data are
extrapolated to produce population estimates for each modeled year.

These population count grids contain estimates of the number of persons per
30 arc-second grid cell, consistent with national censuses and population
registers with respect to relative spatial distribution but adjusted to
match the 2015 Revision of UN World Population Prospects country totals.
There is one image for each modeled year.