-29.91% is the change from 321 to 225
Calculation steps:
[( 225 - 321 ) ÷ 321] x 100 = -29.91%
Formula
Percentage change = [(225 - 321) / 321] x 100
Subtract the new number by the original number
225 - 321 = -96
-96 ÷ 321 = -0.29906542056074764
-0.29906542056074764 x 100 = -29.91%