2961.9% is the change from 21 to 643
Calculation steps:
[( 643 - 21 ) ÷ 21] x 100 = 2961.9%
Formula
Percentage change = [(643 - 21) / 21] x 100
Subtract the new number by the original number
643 - 21 = 622
622 ÷ 21 = 29.61904761904762
29.61904761904762 x 100 = 2961.9%