What is the size of different age groups?

The size of different age groups varies significantly depending on the demographic context and region. Generally, populations are often divided into segments such as children (0-14 years), working-age adults (15-64 years), and seniors (65 years and older). In many developed countries, the proportion of older adults is increasing due to longer life expectancies, while some developing nations may have a larger proportion of children and young adults. Specific statistics can be obtained from national census data or demographic studies relevant to the area of interest.