Which country has the "youngest" population, that is, the highest proportion of population under age 15? which country has the "oldest" population? that is, the highest proportion of population over age 65?

Aregion is an area of land that has common features. these features can be natural, such as climate or landscape. they can also be artificial, such as language or religion. the xinjiang uyghur autonomous region, above, is an area of china inhabited by uyghurs, a muslim group with ethnic ties to turkish people.