The pyramids show the age distribution of the place, which can help in understanding and predicting the development of a country.
There are three types of population pyramids:
- Stationary pyramid shows a constant population, with equal birth rate and death rate
- Expansive pyramid shows a growing population
- Constrictive pyramid shows a shrinking population
In this type of graph, a wide base means a very high birth rate and a narrow base means a low birth rate.