For which of the following decades did the percentage decadal growth of population in India register the sharpest decline since independence?

The decadal population growth rate of India has been continuously declining after peaking in the 1961–1971 era. The sharpest drop/decline in terms of percentage points post-independence was recorded during the 2001–2011 decade, falling from 21.54% in 1991–2001 to 17.7% in 2001–2011 (a drop of 3.84 percentage points).