2.47% is the change from 811 to 831
Calculation steps:
[( 831 - 811 ) ÷ 811] x 100 = 2.47%
Formula
Percentage change = [(831 - 811) / 811] x 100
Subtract the new number by the original number
831 - 811 = 20
20 ÷ 811 = 0.02466091245376079
0.02466091245376079 x 100 = 2.47%