19.19% is the change from 521 to 621
Calculation steps:
[( 621 - 521 ) ÷ 521] x 100 = 19.19%
Formula
Percentage change = [(621 - 521) / 521] x 100
Subtract the new number by the original number
621 - 521 = 100
100 ÷ 521 = 0.19193857965451055
0.19193857965451055 x 100 = 19.19%