-91.42% is the change from 921 to 79
Calculation steps:
[( 79 - 921 ) ÷ 921] x 100 = -91.42%
Formula
Percentage change = [(79 - 921) / 921] x 100
Subtract the new number by the original number
79 - 921 = -842
-842 ÷ 921 = -0.9142236699239956
-0.9142236699239956 x 100 = -91.42%