出典:Wiktionary
population pyramid (複数形 population pyramids)
出典:Wikipedia
出典:『Wikipedia』 (2011/07/20 12:33 UTC 版)
A population pyramid, also called an age structure diagram, is a graphical illustration that shows the distribution of various age groups in a human population (typically that of a country or region of the world), which ideally forms the shape of a pyramid when the region is healthy. It is also used in Ecology to determine the overall age distribution of a population; an indication of the reproductive capabilities and likelihood of the continuation of a species.