2015% is the change from 20 to 423
Calculation steps:
[( 423 - 20 ) ÷ 20] x 100 = 2015%
Formula
Percentage change = [(423 - 20) / 20] x 100
Subtract the new number by the original number
423 - 20 = 403
403 ÷ 20 = 20.15
20.15 x 100 = 2015%
Example