-70.09% is the change from 856 to 256
Calculation steps:
[( 256 - 856 ) ÷ 856] x 100 = -70.09%
Formula
Percentage change = [(256 - 856) / 856] x 100
Subtract the new number by the original number
256 - 856 = -600
-600 ÷ 856 = -0.7009345794392523
-0.7009345794392523 x 100 = -70.09%