-91.28% is the change from 321 to 28
Calculation steps:
[( 28 - 321 ) ÷ 321] x 100 = -91.28%
Formula
Percentage change = [(28 - 321) / 321] x 100
Subtract the new number by the original number
28 - 321 = -293
-293 ÷ 321 = -0.9127725856697819
-0.9127725856697819 x 100 = -91.28%