-99.9% is the change from 980 to 1
Calculation steps:
[( 1 - 980 ) ÷ 980] x 100 = -99.9%
Formula
Percentage change = [(1 - 980) / 980] x 100
Subtract the new number by the original number
1 - 980 = -979
-979 ÷ 980 = -0.9989795918367347
-0.9989795918367347 x 100 = -99.9%