31.71% is the change from 391 to 515
Calculation steps:
[( 515 - 391 ) ÷ 391] x 100 = 31.71%
Formula
Percentage change = [(515 - 391) / 391] x 100
Subtract the new number by the original number
515 - 391 = 124
124 ÷ 391 = 0.3171355498721228
0.3171355498721228 x 100 = 31.71%