-21.12% is the change from 999 to 788
Calculation steps:
[( 788 - 999 ) ÷ 999] x 100 = -21.12%
Formula
Percentage change = [(788 - 999) / 999] x 100
Subtract the new number by the original number
788 - 999 = -211
-211 ÷ 999 = -0.21121121121121122
-0.21121121121121122 x 100 = -21.12%