-76.48% is the change from 421 to 99
Calculation steps:
[( 99 - 421 ) ÷ 421] x 100 = -76.48%
Formula
Percentage change = [(99 - 421) / 421] x 100
Subtract the new number by the original number
99 - 421 = -322
-322 ÷ 421 = -0.7648456057007126
-0.7648456057007126 x 100 = -76.48%