-99.57% is the change from 921 to 4
Calculation steps:
[( 4 - 921 ) ÷ 921] x 100 = -99.57%
Formula
Percentage change = [(4 - 921) / 921] x 100
Subtract the new number by the original number
4 - 921 = -917
-917 ÷ 921 = -0.995656894679696
-0.995656894679696 x 100 = -99.57%