97.39% is the change from 421 to 831
Calculation steps:
[( 831 - 421 ) ÷ 421] x 100 = 97.39%
Formula
Percentage change = [(831 - 421) / 421] x 100
Subtract the new number by the original number
831 - 421 = 410
410 ÷ 421 = 0.9738717339667459
0.9738717339667459 x 100 = 97.39%