3.44% is the change from 320 to 331
Calculation steps:
[( 331 - 320 ) ÷ 320] x 100 = 3.44%
Formula
Percentage change = [(331 - 320) / 320] x 100
Subtract the new number by the original number
331 - 320 = 11
11 ÷ 320 = 0.034375
0.034375 x 100 = 3.44%
Example