With the help of suitable diagrams, explain how the age structures determine the trend of population ?

Explanation

(1) The relative proportion of the individuals of various age groups in the population is called the age structure of that population.
(2) There are three age groups, viz. young or pre-reproductive age group (0 to 14 years), adults or reproductive group (15 to 59 years) and old or post-reproductive group (60 years and above).
(3) The age structure of a population decides the trend of a population.
(4) Based on the distribution of the age groups the populations can be either, growing population, steady population or declining population.
(i) Growing population : Population having larger number of individuals of the pre-reproductive age groups grows at a very rapid rate. Therefore such a population is called a growing population.
(ii) Steady population: When the pre-reproductive age group is larger, the population remains steady.
(iii) Declining population : Larger number of old people and make the number of young people make the population decline.