523.08% is the change from 13 to 81
Calculation steps:
[( 81 - 13 ) ÷ 13] x 100 = 523.08%
Formula
Percentage change = [(81 - 13) / 13] x 100
Subtract the new number by the original number
81 - 13 = 68
68 ÷ 13 = 5.230769230769231
5.230769230769231 x 100 = 523.08%