-49.9% is the change from 990 to 496
Calculation steps:
[( 496 - 990 ) ÷ 990] x 100 = -49.9%
Formula
Percentage change = [(496 - 990) / 990] x 100
Subtract the new number by the original number
496 - 990 = -494
-494 ÷ 990 = -0.498989898989899
-0.498989898989899 x 100 = -49.9%