-96% is the change from 999 to 40
Calculation steps:
[( 40 - 999 ) ÷ 999] x 100 = -96%
Formula
Percentage change = [(40 - 999) / 999] x 100
Subtract the new number by the original number
40 - 999 = -959
-959 ÷ 999 = -0.95995995995996
-0.95995995995996 x 100 = -96%