3284.21% is the change from 19 to 643
Calculation steps:
[( 643 - 19 ) ÷ 19] x 100 = 3284.21%
Formula
Percentage change = [(643 - 19) / 19] x 100
Subtract the new number by the original number
643 - 19 = 624
624 ÷ 19 = 32.8421052631579
32.8421052631579 x 100 = 3284.21%