-79.4% is the change from 806 to 166
Calculation steps:
[( 166 - 806 ) ÷ 806] x 100 = -79.4%
Formula
Percentage change = [(166 - 806) / 806] x 100
Subtract the new number by the original number
166 - 806 = -640
-640 ÷ 806 = -0.794044665012407
-0.794044665012407 x 100 = -79.4%