912.5% is the change from 8 to 81
Calculation steps:
[( 81 - 8 ) ÷ 8] x 100 = 912.5%
Formula
Percentage change = [(81 - 8) / 8] x 100
Subtract the new number by the original number
81 - 8 = 73
73 ÷ 8 = 9.125
9.125 x 100 = 912.5%
Example