0.24% is the change from 420 to 421
Calculation steps:
[( 421 - 420 ) ÷ 420] x 100 = 0.24%
Formula
Percentage change = [(421 - 420) / 420] x 100
Subtract the new number by the original number
421 - 420 = 1
1 ÷ 420 = 0.002380952380952381
0.002380952380952381 x 100 = 0.24%