-18.39% is the change from 870 to 710
Calculation steps:
[( 710 - 870 ) ÷ 870] x 100 = -18.39%
Formula
Percentage change = [(710 - 870) / 870] x 100
Subtract the new number by the original number
710 - 870 = -160
-160 ÷ 870 = -0.1839080459770115
-0.1839080459770115 x 100 = -18.39%