-12.19% is the change from 320 to 281
Calculation steps:
[( 281 - 320 ) ÷ 320] x 100 = -12.19%
Formula
Percentage change = [(281 - 320) / 320] x 100
Subtract the new number by the original number
281 - 320 = -39
-39 ÷ 320 = -0.121875
-0.121875 x 100 = -12.19%