-99.9% is the change from 978 to 1
Calculation steps:
[( 1 - 978 ) ÷ 978] x 100 = -99.9%
Formula
Percentage change = [(1 - 978) / 978] x 100
Subtract the new number by the original number
1 - 978 = -977
-977 ÷ 978 = -0.9989775051124744
-0.9989775051124744 x 100 = -99.9%