-29.69% is the change from 320 to 225
Calculation steps:
[( 225 - 320 ) ÷ 320] x 100 = -29.69%
Formula
Percentage change = [(225 - 320) / 320] x 100
Subtract the new number by the original number
225 - 320 = -95
-95 ÷ 320 = -0.296875
-0.296875 x 100 = -29.69%