-68.39% is the change from 813 to 257
Calculation steps:
[( 257 - 813 ) ÷ 813] x 100 = -68.39%
Formula
Percentage change = [(257 - 813) / 813] x 100
Subtract the new number by the original number
257 - 813 = -556
-556 ÷ 813 = -0.6838868388683886
-0.6838868388683886 x 100 = -68.39%