-79.79% is the change from 851 to 172
Calculation steps:
[( 172 - 851 ) ÷ 851] x 100 = -79.79%
Formula
Percentage change = [(172 - 851) / 851] x 100
Subtract the new number by the original number
172 - 851 = -679
-679 ÷ 851 = -0.7978848413631022
-0.7978848413631022 x 100 = -79.79%