-98.55% is the change from 620 to 9
Calculation steps:
[( 9 - 620 ) ÷ 620] x 100 = -98.55%
Formula
Percentage change = [(9 - 620) / 620] x 100
Subtract the new number by the original number
9 - 620 = -611
-611 ÷ 620 = -0.9854838709677419
-0.9854838709677419 x 100 = -98.55%