-86.47% is the change from 399 to 54
Calculation steps:
[( 54 - 399 ) ÷ 399] x 100 = -86.47%
Formula
Percentage change = [(54 - 399) / 399] x 100
Subtract the new number by the original number
54 - 399 = -345
-345 ÷ 399 = -0.8646616541353384
-0.8646616541353384 x 100 = -86.47%