-99.9% is the change from 970 to 1
Calculation steps:
[( 1 - 970 ) ÷ 970] x 100 = -99.9%
Formula
Percentage change = [(1 - 970) / 970] x 100
Subtract the new number by the original number
1 - 970 = -969
-969 ÷ 970 = -0.9989690721649485
-0.9989690721649485 x 100 = -99.9%