-97.86% is the change from 421 to 9
Calculation steps:
[( 9 - 421 ) ÷ 421] x 100 = -97.86%
Formula
Percentage change = [(9 - 421) / 421] x 100
Subtract the new number by the original number
9 - 421 = -412
-412 ÷ 421 = -0.9786223277909739
-0.9786223277909739 x 100 = -97.86%