Increase number in cell, based on value in adjacent cell

[scottyb]

I have a need to change a number of cells that in one column, but not one after the other, there are blanks, headers, and others bits of information that need to remain. The only cells I want to change have the same text in the column next to them, so I guess if I could get a formula that could change based on this label, I could achieve what I need. Example as below:-

So where it says Title 2, I want to increase the value in the cells in column L next to it 13%.

Any help much appreciated, as the data i have is well over 1500 lines.
Column K Column L
Title 1 176.30
Title 2 8.35
New Menu
Title 1 219.00
Title 2 23.90
New Page
Title 1 9.22


Maybe clearer in the image,