108.27% is the change from 399 to 831
Calculation steps:
[( 831 - 399 ) ÷ 399] x 100 = 108.27%
Formula
Percentage change = [(831 - 399) / 399] x 100
Subtract the new number by the original number
831 - 399 = 432
432 ÷ 399 = 1.0827067669172932
1.0827067669172932 x 100 = 108.27%