-68.96% is the change from 828 to 257
Calculation steps:
[( 257 - 828 ) ÷ 828] x 100 = -68.96%
Formula
Percentage change = [(257 - 828) / 828] x 100
Subtract the new number by the original number
257 - 828 = -571
-571 ÷ 828 = -0.6896135265700483
-0.6896135265700483 x 100 = -68.96%