-15.98% is the change from 870 to 731
Calculation steps:
[( 731 - 870 ) ÷ 870] x 100 = -15.98%
Formula
Percentage change = [(731 - 870) / 870] x 100
Subtract the new number by the original number
731 - 870 = -139
-139 ÷ 870 = -0.15977011494252874
-0.15977011494252874 x 100 = -15.98%