Decadal growth rate
Also called: Decennial growth rate · Topic: Population of India: Distribution, Density, Growth and Composition · NCERT: Class 12, Ch 1 "Population: Distribution, Density, Growth and Composition"
Meaning
The decadal growth rate is how much a population grows in ten years, shown as a percentage. It is found with this formula: g = (P2 − P1) ÷ P1 × 100. Here P1 is the population at the first census and P2 is the population ten years later. India counts its people once every ten years, so this is the main way to compare growth from one census to the next. It shows whether growth is speeding up or slowing down.
Example
India's decadal growth rate peaked at 24.80% in 1961-71. It fell to 17.64% in 2001-11, when the population reached 1,210 million. In 1991-2001, Kerala, on India's south-western coast, had the lowest growth of any state (9.4%).
Don't confuse with
- Annual growth rate: this is growth in one year (India's was 1.64% in 2011). The decadal rate covers ten years.
- Doubling time: this is the number of years a population takes to double at its present yearly rate (about 70 ÷ the yearly growth rate in %). It is not a percentage.
Related concepts
- Population growth
- Stagnant phase of population growth
- Steady growth phase
- Population explosion phase
- Phase of declining growth