-95.16% is the change from 310 to 15
Calculation steps:
[( 15 - 310 ) ÷ 310] x 100 = -95.16%
Formula
Percentage change = [(15 - 310) / 310] x 100
Subtract the new number by the original number
15 - 310 = -295
-295 ÷ 310 = -0.9516129032258065
-0.9516129032258065 x 100 = -95.16%