-2.74% is the change from 329 to 320
Calculation steps:
[( 320 - 329 ) ÷ 329] x 100 = -2.74%
Formula
Percentage change = [(320 - 329) / 329] x 100
Subtract the new number by the original number
320 - 329 = -9
-9 ÷ 329 = -0.02735562310030395
-0.02735562310030395 x 100 = -2.74%