-97.9% is the change from 429 to 9
Calculation steps:
[( 9 - 429 ) ÷ 429] x 100 = -97.9%
Formula
Percentage change = [(9 - 429) / 429] x 100
Subtract the new number by the original number
9 - 429 = -420
-420 ÷ 429 = -0.9790209790209791
-0.9790209790209791 x 100 = -97.9%