Birth rate
As of 2017, Niger has the highest birth rate in the world with 49.443 per thousand people. 
Japan has one of the lowest birth rates in the world with 8 per thousand people.
While in Japan there are 126 million people and in Niger 21 million, both countries had around 1 million babies born in 2016.
Teenage pregnancy
The rates of early marriage and pregnancy in some Asian countries are high. In recent years, the rates have decreased sharply in Indonesia and Malaysia, although it remains relatively high in the former. However, in the industrialized Asian nations such as South Korea and Singapore, teenage birth rates remain among the lowest in the world.