-50.5% is the change from 808 to 400
Calculation steps:
[( 400 - 808 ) ÷ 808] x 100 = -50.5%
Formula
Percentage change = [(400 - 808) / 808] x 100
Subtract the new number by the original number
400 - 808 = -408
-408 ÷ 808 = -0.504950495049505
-0.504950495049505 x 100 = -50.5%