-70.73% is the change from 878 to 257
Calculation steps:
[( 257 - 878 ) ÷ 878] x 100 = -70.73%
Formula
Percentage change = [(257 - 878) / 878] x 100
Subtract the new number by the original number
257 - 878 = -621
-621 ÷ 878 = -0.7072892938496583
-0.7072892938496583 x 100 = -70.73%