-22.92% is the change from 397 to 306
Calculation steps:
[( 306 - 397 ) ÷ 397] x 100 = -22.92%
Formula
Percentage change = [(306 - 397) / 397] x 100
Subtract the new number by the original number
306 - 397 = -91
-91 ÷ 397 = -0.22921914357682618
-0.22921914357682618 x 100 = -22.92%