4.09% is the change from 318 to 331
Calculation steps:
[( 331 - 318 ) ÷ 318] x 100 = 4.09%
Formula
Percentage change = [(331 - 318) / 318] x 100
Subtract the new number by the original number
331 - 318 = 13
13 ÷ 318 = 0.040880503144654086
0.040880503144654086 x 100 = 4.09%