-50.91% is the change from 990 to 486
Calculation steps:
[( 486 - 990 ) ÷ 990] x 100 = -50.91%
Formula
Percentage change = [(486 - 990) / 990] x 100
Subtract the new number by the original number
486 - 990 = -504
-504 ÷ 990 = -0.509090909090909
-0.509090909090909 x 100 = -50.91%