Morgan Housel wrote a few months ago about three forces shaping the world. One of them was the changing demographics of different countries.

Our World in Data published a detailed interactive report on the age structures of countries around the world. There are many important insights here, one of which is there will be many more older people. People are living healthier lives due to better food quality and healthcare. For the first time there are more people over 64 than children younger than 5. The population pyramid visualizes this nicely:

Age Population Pyramid