-98.13% is the change from 800 to 15
Calculation steps:
[( 15 - 800 ) ÷ 800] x 100 = -98.13%
Formula
Percentage change = [(15 - 800) / 800] x 100
Subtract the new number by the original number
15 - 800 = -785
-785 ÷ 800 = -0.98125
-0.98125 x 100 = -98.13%