-97.61% is the change from 879 to 21
Calculation steps:
[( 21 - 879 ) ÷ 879] x 100 = -97.61%
Formula
Percentage change = [(21 - 879) / 879] x 100
Subtract the new number by the original number
21 - 879 = -858
-858 ÷ 879 = -0.9761092150170648
-0.9761092150170648 x 100 = -97.61%