-50.2% is the change from 990 to 493
Calculation steps:
[( 493 - 990 ) ÷ 990] x 100 = -50.2%
Formula
Percentage change = [(493 - 990) / 990] x 100
Subtract the new number by the original number
493 - 990 = -497
-497 ÷ 990 = -0.502020202020202
-0.502020202020202 x 100 = -50.2%