-45.07% is the change from 821 to 451
Calculation steps:
[( 451 - 821 ) ÷ 821] x 100 = -45.07%
Formula
Percentage change = [(451 - 821) / 821] x 100
Subtract the new number by the original number
451 - 821 = -370
-370 ÷ 821 = -0.45066991473812423
-0.45066991473812423 x 100 = -45.07%