8.31% is the change from 421 to 456
Calculation steps:
[( 456 - 421 ) ÷ 421] x 100 = 8.31%
Formula
Percentage change = [(456 - 421) / 421] x 100
Subtract the new number by the original number
456 - 421 = 35
35 ÷ 421 = 0.0831353919239905
0.0831353919239905 x 100 = 8.31%