Age-sex distribution

A very common way of obtaining data to have an insight into population structure and predict its trend consists of collecting information on numbers of individuals by age and sex over a period of time.

The relative number of individuals for each age category informs about population growth:

Figure 1 - Rapid growth

Rapid growth is characterized by a triangular shape, with many young individuals and few old individuals.

Figure 2 - Negative growth

Negative growth is characterized by a similar distribution of individuals across the top and bottom age groups, with a wider area in the middle.

Figure 3 - Slow growth

Slow growth is characterized by a similar distribution of individuals across all age groups.