-9.28% is the change from 431 to 391
Calculation steps:
[( 391 - 431 ) ÷ 431] x 100 = -9.28%
Formula
Percentage change = [(391 - 431) / 431] x 100
Subtract the new number by the original number
391 - 431 = -40
-40 ÷ 431 = -0.09280742459396751
-0.09280742459396751 x 100 = -9.28%