-11.11% is the change from 99 to 88
Calculation steps:
[( 88 - 99 ) ÷ 99] x 100 = -11.11%
Formula
Percentage change = [(88 - 99) / 99] x 100
Subtract the new number by the original number
88 - 99 = -11
-11 ÷ 99 = -0.1111111111111111
-0.1111111111111111 x 100 = -11.11%