-83.95% is the change from 617 to 99
Calculation steps:
[( 99 - 617 ) ÷ 617] x 100 = -83.95%
Formula
Percentage change = [(99 - 617) / 617] x 100
Subtract the new number by the original number
99 - 617 = -518
-518 ÷ 617 = -0.839546191247974
-0.839546191247974 x 100 = -83.95%