-79.08% is the change from 999 to 209
Calculation steps:
[( 209 - 999 ) ÷ 999] x 100 = -79.08%
Formula
Percentage change = [(209 - 999) / 999] x 100
Subtract the new number by the original number
209 - 999 = -790
-790 ÷ 999 = -0.7907907907907908
-0.7907907907907908 x 100 = -79.08%