3220% is the change from 20 to 664
Calculation steps:
[( 664 - 20 ) ÷ 20] x 100 = 3220%
Formula
Percentage change = [(664 - 20) / 20] x 100
Subtract the new number by the original number
664 - 20 = 644
644 ÷ 20 = 32.2
32.2 x 100 = 3220%
Example