-50.24% is the change from 820 to 408
Calculation steps:
[( 408 - 820 ) ÷ 820] x 100 = -50.24%
Formula
Percentage change = [(408 - 820) / 820] x 100
Subtract the new number by the original number
408 - 820 = -412
-412 ÷ 820 = -0.5024390243902439
-0.5024390243902439 x 100 = -50.24%