3095% is the change from 20 to 639
Calculation steps:
[( 639 - 20 ) ÷ 20] x 100 = 3095%
Formula
Percentage change = [(639 - 20) / 20] x 100
Subtract the new number by the original number
639 - 20 = 619
619 ÷ 20 = 30.95
30.95 x 100 = 3095%
Example