812.09% is the change from 91 to 830
Calculation steps:
[( 830 - 91 ) ÷ 91] x 100 = 812.09%
Formula
Percentage change = [(830 - 91) / 91] x 100
Subtract the new number by the original number
830 - 91 = 739
739 ÷ 91 = 8.12087912087912
8.12087912087912 x 100 = 812.09%