-51.4% is the change from 823 to 400
Calculation steps:
[( 400 - 823 ) ÷ 823] x 100 = -51.4%
Formula
Percentage change = [(400 - 823) / 823] x 100
Subtract the new number by the original number
400 - 823 = -423
-423 ÷ 823 = -0.5139732685297691
-0.5139732685297691 x 100 = -51.4%