First: work out the difference (increase) between the two numbers you are comparing.
Increase = New Number - Original Number
Then: divide the increase by the original number and multiply the answer by 100.
% increase = Increase ÷ Original Number × 100.
Increase = $10.25 - $9
% increase= $1.25/$9 x 100
% increase=13.888888889
% increase= 14%