Median Age Around the World, Today’s map, which comes from Global Post, uses CIA Factbook data to show the median age in countries around the world.Per the CIA Factbook, the world’s 15 youngest countries are all in Africa, while Germany and Japan are the oldest. Khosla goes on to discuss potential problems at both ends of the spectrum: large blocks of unemployed young people can lead to unrest, while older populations and declining birth rates have their own economic impact. The Afternoon Map is a semi-regular feature in which we post maps and infographics. In the afternoon. Semi-regularly.