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.
Sub-Saharan Africa
Sub-Saharan African countries top the list of countries and territories by fertility rate with 40 of the highest 50, all with TFR greater than 4 in 2008. All are above the world average except South Africa and Seychelles. More than 40% of the population in sub-Saharan countries is younger than 15 years old, as well as in Sudan, with the exception of South Africa.