3947.62% is the change from 21 to 850
Calculation steps:
[( 850 - 21 ) ÷ 21] x 100 = 3947.62%
Formula
Percentage change = [(850 - 21) / 21] x 100
Subtract the new number by the original number
850 - 21 = 829
829 ÷ 21 = 39.476190476190474
39.476190476190474 x 100 = 3947.62%