-18.04% is the change from 388 to 318
Calculation steps:
[( 318 - 388 ) ÷ 388] x 100 = -18.04%
Formula
Percentage change = [(318 - 388) / 388] x 100
Subtract the new number by the original number
318 - 388 = -70
-70 ÷ 388 = -0.18041237113402062
-0.18041237113402062 x 100 = -18.04%