-90.08% is the change from 998 to 99
Calculation steps:
[( 99 - 998 ) ÷ 998] x 100 = -90.08%
Formula
Percentage change = [(99 - 998) / 998] x 100
Subtract the new number by the original number
99 - 998 = -899
-899 ÷ 998 = -0.9008016032064128
-0.9008016032064128 x 100 = -90.08%