-10.11% is the change from 89 to 80
Calculation steps:
[( 80 - 89 ) ÷ 89] x 100 = -10.11%
Formula
Percentage change = [(80 - 89) / 89] x 100
Subtract the new number by the original number
80 - 89 = -9
-9 ÷ 89 = -0.10112359550561797
-0.10112359550561797 x 100 = -10.11%