29.03% is the change from 31 to 40
Calculation steps:
[( 40 - 31 ) ÷ 31] x 100 = 29.03%
Formula
Percentage change = [(40 - 31) / 31] x 100
Subtract the new number by the original number
40 - 31 = 9
9 ÷ 31 = 0.2903225806451613
0.2903225806451613 x 100 = 29.03%