-99.9% is the change from 988 to 1
Calculation steps:
[( 1 - 988 ) ÷ 988] x 100 = -99.9%
Formula
Percentage change = [(1 - 988) / 988] x 100
Subtract the new number by the original number
1 - 988 = -987
-987 ÷ 988 = -0.9989878542510121
-0.9989878542510121 x 100 = -99.9%