-51.62% is the change from 831 to 402
Calculation steps:
[( 402 - 831 ) ÷ 831] x 100 = -51.62%
Formula
Percentage change = [(402 - 831) / 831] x 100
Subtract the new number by the original number
402 - 831 = -429
-429 ÷ 831 = -0.516245487364621
-0.516245487364621 x 100 = -51.62%