9% is the change from 100 to 109
Calculation steps:
[( 109 - 100 ) ÷ 100] x 100 = 9%
Formula
Percentage change = [(109 - 100) / 100] x 100
Subtract the new number by the original number
109 - 100 = 9
9 ÷ 100 = 0.09
0.09 x 100 = 9%
Example