-97.49% is the change from 399 to 10
Calculation steps:
[( 10 - 399 ) ÷ 399] x 100 = -97.49%
Formula
Percentage change = [(10 - 399) / 399] x 100
Subtract the new number by the original number
10 - 399 = -389
-389 ÷ 399 = -0.974937343358396
-0.974937343358396 x 100 = -97.49%