36.25% is the change from 80 to 109
Calculation steps:
[( 109 - 80 ) ÷ 80] x 100 = 36.25%
Formula
Percentage change = [(109 - 80) / 80] x 100
Subtract the new number by the original number
109 - 80 = 29
29 ÷ 80 = 0.3625
0.3625 x 100 = 36.25%
Example