-80.21% is the change from 839 to 166
Calculation steps:
[( 166 - 839 ) ÷ 839] x 100 = -80.21%
Formula
Percentage change = [(166 - 839) / 839] x 100
Subtract the new number by the original number
166 - 839 = -673
-673 ÷ 839 = -0.8021454112038141
-0.8021454112038141 x 100 = -80.21%