19.52% is the change from 420 to 502
Calculation steps:
[( 502 - 420 ) ÷ 420] x 100 = 19.52%
Formula
Percentage change = [(502 - 420) / 420] x 100
Subtract the new number by the original number
502 - 420 = 82
82 ÷ 420 = 0.19523809523809524
0.19523809523809524 x 100 = 19.52%