21.9% is the change from 420 to 512
Calculation steps:
[( 512 - 420 ) ÷ 420] x 100 = 21.9%
Formula
Percentage change = [(512 - 420) / 420] x 100
Subtract the new number by the original number
512 - 420 = 92
92 ÷ 420 = 0.21904761904761905
0.21904761904761905 x 100 = 21.9%