-87.9% is the change from 686 to 83
Calculation steps:
[( 83 - 686 ) ÷ 686] x 100 = -87.9%
Formula
Percentage change = [(83 - 686) / 686] x 100
Subtract the new number by the original number
83 - 686 = -603
-603 ÷ 686 = -0.8790087463556852
-0.8790087463556852 x 100 = -87.9%