-99.6% is the change from 993 to 4
Calculation steps:
[( 4 - 993 ) ÷ 993] x 100 = -99.6%
Formula
Percentage change = [(4 - 993) / 993] x 100
Subtract the new number by the original number
4 - 993 = -989
-989 ÷ 993 = -0.9959718026183283
-0.9959718026183283 x 100 = -99.6%