29.92% is the change from 391 to 508
Calculation steps:
[( 508 - 391 ) ÷ 391] x 100 = 29.92%
Formula
Percentage change = [(508 - 391) / 391] x 100
Subtract the new number by the original number
508 - 391 = 117
117 ÷ 391 = 0.29923273657289
0.29923273657289 x 100 = 29.92%