15.56% is the change from 135 to 156
Calculation steps:
[( 156 - 135 ) ÷ 135] x 100 = 15.56%
Formula
Percentage change = [(156 - 135) / 135] x 100
Subtract the new number by the original number
156 - 135 = 21
21 ÷ 135 = 0.15555555555555556
0.15555555555555556 x 100 = 15.56%