The Demographic Transition
The dependency ratio is the ratio between people who are too young or too old to work versus people who are the right age to work.
The sex ratio of a country is the number of males per one hundred females.
The demographic transition is a process with several stages and every country is in one of the stages. (Other than the first one)
Potential Stage Five
Stage 5 would be what would occur when the population starts rising again. This will result in a rising birth rate, low death rate, and stable or slow increase.