-97.56% is the change from 861 to 21
Calculation steps:
[( 21 - 861 ) ÷ 861] x 100 = -97.56%
Formula
Percentage change = [(21 - 861) / 861] x 100
Subtract the new number by the original number
21 - 861 = -840
-840 ÷ 861 = -0.975609756097561
-0.975609756097561 x 100 = -97.56%