-55.48% is the change from 310 to 138
Calculation steps:
[( 138 - 310 ) ÷ 310] x 100 = -55.48%
Formula
Percentage change = [(138 - 310) / 310] x 100
Subtract the new number by the original number
138 - 310 = -172
-172 ÷ 310 = -0.5548387096774193
-0.5548387096774193 x 100 = -55.48%