-55.16% is the change from 310 to 139
Calculation steps:
[( 139 - 310 ) ÷ 310] x 100 = -55.16%
Formula
Percentage change = [(139 - 310) / 310] x 100
Subtract the new number by the original number
139 - 310 = -171
-171 ÷ 310 = -0.5516129032258065
-0.5516129032258065 x 100 = -55.16%