-31.03% is the change from 406 to 280
Calculation steps:
[( 280 - 406 ) ÷ 406] x 100 = -31.03%
Formula
Percentage change = [(280 - 406) / 406] x 100
Subtract the new number by the original number
280 - 406 = -126
-126 ÷ 406 = -0.3103448275862069
-0.3103448275862069 x 100 = -31.03%