-31.03% is the change from 870 to 600
Calculation steps:
[( 600 - 870 ) ÷ 870] x 100 = -31.03%
Formula
Percentage change = [(600 - 870) / 870] x 100
Subtract the new number by the original number
600 - 870 = -270
-270 ÷ 870 = -0.3103448275862069
-0.3103448275862069 x 100 = -31.03%