-99.6% is the change from 998 to 4
Calculation steps:
[( 4 - 998 ) ÷ 998] x 100 = -99.6%
Formula
Percentage change = [(4 - 998) / 998] x 100
Subtract the new number by the original number
4 - 998 = -994
-994 ÷ 998 = -0.9959919839679359
-0.9959919839679359 x 100 = -99.6%