-30.31% is the change from 320 to 223
Calculation steps:
[( 223 - 320 ) ÷ 320] x 100 = -30.31%
Formula
Percentage change = [(223 - 320) / 320] x 100
Subtract the new number by the original number
223 - 320 = -97
-97 ÷ 320 = -0.303125
-0.303125 x 100 = -30.31%