Variations at the economy level.

Currently, economies across the world are in different phases of Demographic transition, and total fertility rates vary significantly. Fertility decline is particularly pronounced in some places, where total fertility rates have fallen below the replacement level of 2.1 children per woman (the replacement level fertility is the average number of children per woman needed to maintain a stable population size). In 2023, in seven economies, on average, a woman gave birth to less than one child. On the other hand, there were five economies where, on average, a woman gave birth to more than six children. These economies with fertility rates higher than six were all in the Sub-Saharan Africa region.