-90.72% is the change from 851 to 79
Calculation steps:
[( 79 - 851 ) ÷ 851] x 100 = -90.72%
Formula
Percentage change = [(79 - 851) / 851] x 100
Subtract the new number by the original number
79 - 851 = -772
-772 ÷ 851 = -0.9071680376028202
-0.9071680376028202 x 100 = -90.72%