-50.71% is the change from 990 to 488
Calculation steps:
[( 488 - 990 ) ÷ 990] x 100 = -50.71%
Formula
Percentage change = [(488 - 990) / 990] x 100
Subtract the new number by the original number
488 - 990 = -502
-502 ÷ 990 = -0.5070707070707071
-0.5070707070707071 x 100 = -50.71%