-40.34% is the change from 999 to 596
Calculation steps:
[( 596 - 999 ) ÷ 999] x 100 = -40.34%
Formula
Percentage change = [(596 - 999) / 999] x 100
Subtract the new number by the original number
596 - 999 = -403
-403 ÷ 999 = -0.4034034034034034
-0.4034034034034034 x 100 = -40.34%