99.05% is the change from 421 to 838
Calculation steps:
[( 838 - 421 ) ÷ 421] x 100 = 99.05%
Formula
Percentage change = [(838 - 421) / 421] x 100
Subtract the new number by the original number
838 - 421 = 417
417 ÷ 421 = 0.9904988123515439
0.9904988123515439 x 100 = 99.05%