-92.13% is the change from 839 to 66
Calculation steps:
[( 66 - 839 ) ÷ 839] x 100 = -92.13%
Formula
Percentage change = [(66 - 839) / 839] x 100
Subtract the new number by the original number
66 - 839 = -773
-773 ÷ 839 = -0.9213349225268176
-0.9213349225268176 x 100 = -92.13%