This article is a list of countries by median age.It is the only index associated with the age distribution of a population.[1] Currently, the median age ranges from a low of about 18 or less in most Least Developed countries to 40 or more in most European countries, Canada, Cuba, Hong Kong, Japan, South Korea, Taiwan, and Thailand.[2][3] The median age of women tends to be much greater than that of men in some of the ex-Soviet republics, while in the Global South, the difference is far smaller or is reversed.In this article, two sets of data based on Central Intelligence Agency (CIA) and United Nations (UN) estimates are provided.