3780.95% is the change from 21 to 815
Calculation steps:
[( 815 - 21 ) ÷ 21] x 100 = 3780.95%
Formula
Percentage change = [(815 - 21) / 21] x 100
Subtract the new number by the original number
815 - 21 = 794
794 ÷ 21 = 37.80952380952381
37.80952380952381 x 100 = 3780.95%