-11% is the change from 100 to 89
Calculation steps:
[( 89 - 100 ) ÷ 100] x 100 = -11%
Formula
Percentage change = [(89 - 100) / 100] x 100
Subtract the new number by the original number
89 - 100 = -11
-11 ÷ 100 = -0.11
-0.11 x 100 = -11%
Example