-21.91% is the change from 397 to 310
Calculation steps:
[( 310 - 397 ) ÷ 397] x 100 = -21.91%
Formula
Percentage change = [(310 - 397) / 397] x 100
Subtract the new number by the original number
310 - 397 = -87
-87 ÷ 397 = -0.21914357682619648
-0.21914357682619648 x 100 = -21.91%