-89.78% is the change from 851 to 87
Calculation steps:
[( 87 - 851 ) ÷ 851] x 100 = -89.78%
Formula
Percentage change = [(87 - 851) / 851] x 100
Subtract the new number by the original number
87 - 851 = -764
-764 ÷ 851 = -0.8977673325499412
-0.8977673325499412 x 100 = -89.78%