-50.81% is the change from 990 to 487
Calculation steps:
[( 487 - 990 ) ÷ 990] x 100 = -50.81%
Formula
Percentage change = [(487 - 990) / 990] x 100
Subtract the new number by the original number
487 - 990 = -503
-503 ÷ 990 = -0.5080808080808081
-0.5080808080808081 x 100 = -50.81%