-68.67% is the change from 817 to 256
Calculation steps:
[( 256 - 817 ) ÷ 817] x 100 = -68.67%
Formula
Percentage change = [(256 - 817) / 817] x 100
Subtract the new number by the original number
256 - 817 = -561
-561 ÷ 817 = -0.6866585067319462
-0.6866585067319462 x 100 = -68.67%