-42.35% is the change from 921 to 531
Calculation steps:
[( 531 - 921 ) ÷ 921] x 100 = -42.35%
Formula
Percentage change = [(531 - 921) / 921] x 100
Subtract the new number by the original number
531 - 921 = -390
-390 ÷ 921 = -0.4234527687296417
-0.4234527687296417 x 100 = -42.35%