-38.97% is the change from 870 to 531
Calculation steps:
[( 531 - 870 ) ÷ 870] x 100 = -38.97%
Formula
Percentage change = [(531 - 870) / 870] x 100
Subtract the new number by the original number
531 - 870 = -339
-339 ÷ 870 = -0.3896551724137931
-0.3896551724137931 x 100 = -38.97%