Legendry. I think that might actually work. It's a spreadsheet I have inherited, and is basically the bane of my life. I will have a play and let you know how I get on. Is there a cheeky formula you can apply to change all the values in a column by 1.05% or just copy =Z3*1.05 down all the rows?
I've mocked up how you might go about doing the 5% increase. See Sheet 1 in the attached doc.
I then copied the table with the 5% increase and pasted with values over the current ones to ensure that your source table has been updated with the newest values and not the formulas which will break the spreadsheet.