-50.5% is the change from 992 to 491
Calculation steps:
[( 491 - 992 ) ÷ 992] x 100 = -50.5%
Formula
Percentage change = [(491 - 992) / 992] x 100
Subtract the new number by the original number
491 - 992 = -501
-501 ÷ 992 = -0.5050403225806451
-0.5050403225806451 x 100 = -50.5%