-88.51% is the change from 870 to 100
Calculation steps:
[( 100 - 870 ) ÷ 870] x 100 = -88.51%
Formula
Percentage change = [(100 - 870) / 870] x 100
Subtract the new number by the original number
100 - 870 = -770
-770 ÷ 870 = -0.8850574712643678
-0.8850574712643678 x 100 = -88.51%