-70.61% is the change from 871 to 256
Calculation steps:
[( 256 - 871 ) ÷ 871] x 100 = -70.61%
Formula
Percentage change = [(256 - 871) / 871] x 100
Subtract the new number by the original number
256 - 871 = -615
-615 ÷ 871 = -0.7060849598163031
-0.7060849598163031 x 100 = -70.61%