The correct option is It is the change of population expressed in percentage..
Explanation
Population growth refers to the change in the number of inhabitants of a territory during a specific period of time. This change can be expressed in two distinct ways: in terms of absolute numbers and in terms of percentage. The "Growth Rate of Population" specifically refers to the pace of this change expressed as a percentage.
Option Analysis
- It is the change of population expressed in absolute numbers. is incorrect: The change of population expressed in absolute numbers is simply referred to as "Population Growth" or "Absolute Growth." It is calculated by subtracting the population of an earlier year from that of a later year (e.g., Population in 2011 minus Population in 2001).
- It is the change of population expressed in percentage. is correct: When the change in population is expressed as a percentage of the base population, it is known as the "Growth Rate of Population." For example, an annual growth rate of 2% means that there is an increase of 2 persons for every 100 persons in the base population.
- It is always positive. is incorrect: The growth rate is not always positive. It can be negative if the population decreases between two points in time (negative growth), which occurs when the sum of deaths and out-migration exceeds the sum of births and in-migration.
- It is calculated only every 10 years. is incorrect: While the Census in India is conducted every 10 years, the growth rate can be calculated for any specific duration, such as an annual growth rate or a decadal growth rate. It is not restricted to a ten-year calculation cycle conceptually.
Key Takeaway: "Absolute Growth" measures the total numerical increase in population, whereas "Growth Rate" measures the pace of this change expressed as a percentage.