-68.06% is the change from 310 to 99
Calculation steps:
[( 99 - 310 ) ÷ 310] x 100 = -68.06%
Formula
Percentage change = [(99 - 310) / 310] x 100
Subtract the new number by the original number
99 - 310 = -211
-211 ÷ 310 = -0.6806451612903226
-0.6806451612903226 x 100 = -68.06%