-93.69% is the change from 491 to 31
Calculation steps:
[( 31 - 491 ) ÷ 491] x 100 = -93.69%
Formula
Percentage change = [(31 - 491) / 491] x 100
Subtract the new number by the original number
31 - 491 = -460
-460 ÷ 491 = -0.9368635437881874
-0.9368635437881874 x 100 = -93.69%