-99.88% is the change from 800 to 1
Calculation steps:
[( 1 - 800 ) ÷ 800] x 100 = -99.88%
Formula
Percentage change = [(1 - 800) / 800] x 100
Subtract the new number by the original number
1 - 800 = -799
-799 ÷ 800 = -0.99875
-0.99875 x 100 = -99.88%