-20.65% is the change from 397 to 315
Calculation steps:
[( 315 - 397 ) ÷ 397] x 100 = -20.65%
Formula
Percentage change = [(315 - 397) / 397] x 100
Subtract the new number by the original number
315 - 397 = -82
-82 ÷ 397 = -0.20654911838790932
-0.20654911838790932 x 100 = -20.65%