Doing a YTD sum - vlookup?

I'm trying to do a year to date single-cell reference for a big worksheet based on accounting periods - so this will change each time the sheet is opened.

(see example)

So I am current in P2, and I want to do a year-to-date of each of the line items on another sheet. (all items in column A remain static.) What would the best way of doing it be? I tried a vlookup+vlookup+vlookup+vlookup+... but that formula is far too long.