-98.9% is the change from 909 to 10
Calculation steps:
[( 10 - 909 ) ÷ 909] x 100 = -98.9%
Formula
Percentage change = [(10 - 909) / 909] x 100
Subtract the new number by the original number
10 - 909 = -899
-899 ÷ 909 = -0.988998899889989
-0.988998899889989 x 100 = -98.9%