-87.19% is the change from 999 to 128
Calculation steps:
[( 128 - 999 ) ÷ 999] x 100 = -87.19%
Formula
Percentage change = [(128 - 999) / 999] x 100
Subtract the new number by the original number
128 - 999 = -871
-871 ÷ 999 = -0.8718718718718719
-0.8718718718718719 x 100 = -87.19%