67.9% is the change from 81 to 136
Calculation steps:
[( 136 - 81 ) ÷ 81] x 100 = 67.9%
Formula
Percentage change = [(136 - 81) / 81] x 100
Subtract the new number by the original number
136 - 81 = 55
55 ÷ 81 = 0.6790123456790124
0.6790123456790124 x 100 = 67.9%