What do you think, why is knowledge about the age structure of the country’s population necessary?

Knowledge about the age composition of the population is needed in order to properly distribute costs, and plan the budget in particular and the entire economy as a whole. You need to know how many able-bodied people there are, and how many retirees. Indeed, thanks to the able-bodied population, the country earns money, and spends it on pensioners by paying them pensions. You also need to know how many children and what age, so that there is a sufficient number of schools and kindergartens, as well as to plan the cost of education.