-98.5% is the change from 998 to 15
Calculation steps:
[( 15 - 998 ) ÷ 998] x 100 = -98.5%
Formula
Percentage change = [(15 - 998) / 998] x 100
Subtract the new number by the original number
15 - 998 = -983
-983 ÷ 998 = -0.9849699398797596
-0.9849699398797596 x 100 = -98.5%