-34.69% is the change from 320 to 209
Calculation steps:
[( 209 - 320 ) ÷ 320] x 100 = -34.69%
Formula
Percentage change = [(209 - 320) / 320] x 100
Subtract the new number by the original number
209 - 320 = -111
-111 ÷ 320 = -0.346875
-0.346875 x 100 = -34.69%