19% is the change from 521 to 620
Calculation steps:
[( 620 - 521 ) ÷ 521] x 100 = 19%
Formula
Percentage change = [(620 - 521) / 521] x 100
Subtract the new number by the original number
620 - 521 = 99
99 ÷ 521 = 0.19001919385796545
0.19001919385796545 x 100 = 19%