Population statistics are numbers that matter. They might imperil the future of societies or the future of mankind on Planet Earth.
"Population is the total membership or population or “universe” of a defined class of people, objects or events." OECD, Paris
There is no statistical office that does not monitor the development of its country's population, e.g. the number of inhabitants (males or females), their growth rates and more in-depth differentiations (e.g. by age group, by level of education). It's an objective way of measuring how we live.
World Bank's World Development Indicators database offers population statistics for nearly every country worldwide. Be aware that this database does not cover the latest figures. But that's not critical. It documents the trends.
More details and more recent statistics are provided by Eurostat, the statistical office of the European Union, e.g.:
Population change - Demographic balance and crude rates at national level
Population on 1st January by age groups and sex - cities and greater cities. Eurostat's regional statistics provide population statistics up to EU's NUTS 2 regions Nomenclature of Territorial Units for Statistics 2: counties, government regions.
World population is rising. According to World Bank's statistics 7.24 billion inhabitants populated our planet in 2014. A considerable increase of 1.1 billion people within 14 years only.
To monitor the population development for (nearly) all countries worldwide incl. selected country aggregates (e.g. Arab World, East Asia & Pacific, European Union, Latin America & Caribbean, Middle East & North Africa, South Asia, World) DSI provides a special app on your mobile devices: