3880.95% is the change from 21 to 836
Calculation steps:
[( 836 - 21 ) ÷ 21] x 100 = 3880.95%
Formula
Percentage change = [(836 - 21) / 21] x 100
Subtract the new number by the original number
836 - 21 = 815
815 ÷ 21 = 38.80952380952381
38.80952380952381 x 100 = 3880.95%