-84.07% is the change from 339 to 54
Calculation steps:
[( 54 - 339 ) ÷ 339] x 100 = -84.07%
Formula
Percentage change = [(54 - 339) / 339] x 100
Subtract the new number by the original number
54 - 339 = -285
-285 ÷ 339 = -0.8407079646017699
-0.8407079646017699 x 100 = -84.07%