9.46% is the change from 391 to 428
Calculation steps:
[( 428 - 391 ) ÷ 391] x 100 = 9.46%
Formula
Percentage change = [(428 - 391) / 391] x 100
Subtract the new number by the original number
428 - 391 = 37
37 ÷ 391 = 0.09462915601023018
0.09462915601023018 x 100 = 9.46%