3809.52% is the change from 21 to 821
Calculation steps:
[( 821 - 21 ) ÷ 21] x 100 = 3809.52%
Formula
Percentage change = [(821 - 21) / 21] x 100
Subtract the new number by the original number
821 - 21 = 800
800 ÷ 21 = 38.095238095238095
38.095238095238095 x 100 = 3809.52%