-11.56% is the change from 320 to 283
Calculation steps:
[( 283 - 320 ) ÷ 320] x 100 = -11.56%
Formula
Percentage change = [(283 - 320) / 320] x 100
Subtract the new number by the original number
283 - 320 = -37
-37 ÷ 320 = -0.115625
-0.115625 x 100 = -11.56%