23.52% is the change from 421 to 520
Calculation steps:
[( 520 - 421 ) ÷ 421] x 100 = 23.52%
Formula
Percentage change = [(520 - 421) / 421] x 100
Subtract the new number by the original number
520 - 421 = 99
99 ÷ 421 = 0.23515439429928742
0.23515439429928742 x 100 = 23.52%