-39.31% is the change from 870 to 528
Calculation steps:
[( 528 - 870 ) ÷ 870] x 100 = -39.31%
Formula
Percentage change = [(528 - 870) / 870] x 100
Subtract the new number by the original number
528 - 870 = -342
-342 ÷ 870 = -0.3931034482758621
-0.3931034482758621 x 100 = -39.31%