-2.39% is the change from 879 to 858
Calculation steps:
[( 858 - 879 ) ÷ 879] x 100 = -2.39%
Formula
Percentage change = [(858 - 879) / 879] x 100
Subtract the new number by the original number
858 - 879 = -21
-21 ÷ 879 = -0.023890784982935155
-0.023890784982935155 x 100 = -2.39%