27.81% is the change from 320 to 409
Calculation steps:
[( 409 - 320 ) ÷ 320] x 100 = 27.81%
Formula
Percentage change = [(409 - 320) / 320] x 100
Subtract the new number by the original number
409 - 320 = 89
89 ÷ 320 = 0.278125
0.278125 x 100 = 27.81%