-10.28% is the change from 321 to 288
Calculation steps:
[( 288 - 321 ) ÷ 321] x 100 = -10.28%
Formula
Percentage change = [(288 - 321) / 321] x 100
Subtract the new number by the original number
288 - 321 = -33
-33 ÷ 321 = -0.102803738317757
-0.102803738317757 x 100 = -10.28%