-91.59% is the change from 321 to 27
Calculation steps:
[( 27 - 321 ) ÷ 321] x 100 = -91.59%
Formula
Percentage change = [(27 - 321) / 321] x 100
Subtract the new number by the original number
27 - 321 = -294
-294 ÷ 321 = -0.9158878504672897
-0.9158878504672897 x 100 = -91.59%