-81.71% is the change from 421 to 77
Calculation steps:
[( 77 - 421 ) ÷ 421] x 100 = -81.71%
Formula
Percentage change = [(77 - 421) / 421] x 100
Subtract the new number by the original number
77 - 421 = -344
-344 ÷ 421 = -0.8171021377672208
-0.8171021377672208 x 100 = -81.71%