-2.51% is the change from 398 to 388
Calculation steps:
[( 388 - 398 ) ÷ 398] x 100 = -2.51%
Formula
Percentage change = [(388 - 398) / 398] x 100
Subtract the new number by the original number
388 - 398 = -10
-10 ÷ 398 = -0.02512562814070352
-0.02512562814070352 x 100 = -2.51%