-56.57% is the change from 921 to 400
Calculation steps:
[( 400 - 921 ) ÷ 921] x 100 = -56.57%
Formula
Percentage change = [(400 - 921) / 921] x 100
Subtract the new number by the original number
400 - 921 = -521
-521 ÷ 921 = -0.5656894679695983
-0.5656894679695983 x 100 = -56.57%