-82.93% is the change from 580 to 99
Calculation steps:
[( 99 - 580 ) ÷ 580] x 100 = -82.93%
Formula
Percentage change = [(99 - 580) / 580] x 100
Subtract the new number by the original number
99 - 580 = -481
-481 ÷ 580 = -0.8293103448275863
-0.8293103448275863 x 100 = -82.93%