-83.69% is the change from 607 to 99
Calculation steps:
[( 99 - 607 ) ÷ 607] x 100 = -83.69%
Formula
Percentage change = [(99 - 607) / 607] x 100
Subtract the new number by the original number
99 - 607 = -508
-508 ÷ 607 = -0.8369028006589786
-0.8369028006589786 x 100 = -83.69%