-98.97% is the change from 870 to 9
Calculation steps:
[( 9 - 870 ) ÷ 870] x 100 = -98.97%
Formula
Percentage change = [(9 - 870) / 870] x 100
Subtract the new number by the original number
9 - 870 = -861
-861 ÷ 870 = -0.9896551724137931
-0.9896551724137931 x 100 = -98.97%