3980.95% is the change from 21 to 857
Calculation steps:
[( 857 - 21 ) ÷ 21] x 100 = 3980.95%
Formula
Percentage change = [(857 - 21) / 21] x 100
Subtract the new number by the original number
857 - 21 = 836
836 ÷ 21 = 39.80952380952381
39.80952380952381 x 100 = 3980.95%