-80.29% is the change from 421 to 83
Calculation steps:
[( 83 - 421 ) ÷ 421] x 100 = -80.29%
Formula
Percentage change = [(83 - 421) / 421] x 100
Subtract the new number by the original number
83 - 421 = -338
-338 ÷ 421 = -0.8028503562945368
-0.8028503562945368 x 100 = -80.29%