30.69% is the change from 391 to 511
Calculation steps:
[( 511 - 391 ) ÷ 391] x 100 = 30.69%
Formula
Percentage change = [(511 - 391) / 391] x 100
Subtract the new number by the original number
511 - 391 = 120
120 ÷ 391 = 0.3069053708439898
0.3069053708439898 x 100 = 30.69%