-15.79% is the change from 380 to 320
Calculation steps:
[( 320 - 380 ) ÷ 380] x 100 = -15.79%
Formula
Percentage change = [(320 - 380) / 380] x 100
Subtract the new number by the original number
320 - 380 = -60
-60 ÷ 380 = -0.15789473684210525
-0.15789473684210525 x 100 = -15.79%