Figures used in this chart are based on the most up to date estimate or projections by the national census authority where available, and are usually rounded off. Where updated national data are not available, figures are based on the projections for 2018 by the Population Division of the United Nations Department of Economic and Social Affairs.
Because the compiled figures are not collected at the same time in every country, or at the same level of accuracy, the resulting numerical comparisons may create misleading conclusions. Furthermore, the addition of figures from all countries may not equal the world total. A handful of nations have not conducted a census in over 30 years, providing high error margin estimates only.
Areas that form integral parts of sovereign states, such as the countries of the United Kingdom, are counted as part of the sovereign states concerned. Not included are other entities, such as the European Union,[Note 1]
that are not sovereign states, and independent territories that do not have permanent populations, such as various countries' claims to Antarctica.