-53.22% is the change from 855 to 400
Calculation steps:
[( 400 - 855 ) ÷ 855] x 100 = -53.22%
Formula
Percentage change = [(400 - 855) / 855] x 100
Subtract the new number by the original number
400 - 855 = -455
-455 ÷ 855 = -0.5321637426900585
-0.5321637426900585 x 100 = -53.22%