1828.57% is the change from 21 to 405
Calculation steps:
[( 405 - 21 ) ÷ 21] x 100 = 1828.57%
Formula
Percentage change = [(405 - 21) / 21] x 100
Subtract the new number by the original number
405 - 21 = 384
384 ÷ 21 = 18.285714285714285
18.285714285714285 x 100 = 1828.57%