In case of an increase use this formula
[tex]mutiplier = 1 + \frac{\%}{100} [/tex]
So if the percentage of increase of 6%, the multiplier will be
[tex]1 + \frac{6}{100} = 1.06[/tex]
In case of a decrease, the formula is mostly the same.
[tex]mutiplier = 1 - \frac{\%}{100} [/tex]
So if the percentage of decrease is 6%, the multiplier will be
[tex]1 - \frac{6}{100} = 0.94[/tex]