-68.51% is the change from 813 to 256
Calculation steps:
[( 256 - 813 ) ÷ 813] x 100 = -68.51%
Formula
Percentage change = [(256 - 813) / 813] x 100
Subtract the new number by the original number
256 - 813 = -557
-557 ÷ 813 = -0.6851168511685117
-0.6851168511685117 x 100 = -68.51%