|You might want to be more specific as to what you are actually trying to do.|
PasteSpecial allows you perform some basic mathematical operations on values in cells, but "increase by a specific percentage" isn't one if them.
However, there may be a workaround.
You could calculate 5% of each number on another sheet, perform a PasteSpecial...Values to eliminate the formulas on that sheet and then PasteSpecial...Add those values to the values on the original sheet.
This should work for actual numbers on the original sheet, but might be problematic if the numbers are the result of a formula.
Again, telling us what you really want to do might help us come up with a more specific solution.