-97.62% is the change from 421 to 10
Calculation steps:
[( 10 - 421 ) ÷ 421] x 100 = -97.62%
Formula
Percentage change = [(10 - 421) / 421] x 100
Subtract the new number by the original number
10 - 421 = -411
-411 ÷ 421 = -0.9762470308788599
-0.9762470308788599 x 100 = -97.62%