-79.25% is the change from 800 to 166
Calculation steps:
[( 166 - 800 ) ÷ 800] x 100 = -79.25%
Formula
Percentage change = [(166 - 800) / 800] x 100
Subtract the new number by the original number
166 - 800 = -634
-634 ÷ 800 = -0.7925
-0.7925 x 100 = -79.25%