For area: Encyclopedia Britannica
For population, urban population, percent change in population per year, percent of population under 15 years, life expectancy: Toshiko Kaneda, Charlotte Greenbaum, and Carl Haub, 2022 World Population Data Sheet (Washington, D.C.: Population Reference Bureau, 2022); Reproduced by permission. All rights reserved.
For capital: The World Factbook (Central Intelligence Agency) and Google Maps
For date of origin, literacy rate, per capita GDP: The World Factbook
For languages: The World Factbook; World Book Encyclopedia
For political system: Based on annual editions of Freedom in the World (Freedom House), the World Factbook, and news accounts
For head of government: rulers.org, the World Factbook, and news accounts • For HDI: Human Development Report 2023 (United Nations Development Program)
Most figures are the latest available from each source as of May 2023; Heads of Government as of Sept. 1, 2023.