821.43% is the change from 42 to 387
Calculation steps:
[( 387 - 42 ) ÷ 42] x 100 = 821.43%
Formula
Percentage change = [(387 - 42) / 42] x 100
Subtract the new number by the original number
387 - 42 = 345
345 ÷ 42 = 8.214285714285714
8.214285714285714 x 100 = 821.43%