-1.1% is the change from 999 to 988
Calculation steps:
[( 988 - 999 ) ÷ 999] x 100 = -1.1%
Formula
Percentage change = [(988 - 999) / 999] x 100
Subtract the new number by the original number
988 - 999 = -11
-11 ÷ 999 = -0.011011011011011011
-0.011011011011011011 x 100 = -1.1%