-21.72% is the change from 511 to 400
Calculation steps:
[( 400 - 511 ) ÷ 511] x 100 = -21.72%
Formula
Percentage change = [(400 - 511) / 511] x 100
Subtract the new number by the original number
400 - 511 = -111
-111 ÷ 511 = -0.2172211350293542
-0.2172211350293542 x 100 = -21.72%