-15.9% is the change from 390 to 328
Calculation steps:
[( 328 - 390 ) ÷ 390] x 100 = -15.9%
Formula
Percentage change = [(328 - 390) / 390] x 100
Subtract the new number by the original number
328 - 390 = -62
-62 ÷ 390 = -0.15897435897435896
-0.15897435897435896 x 100 = -15.9%