Ignore blank cells

Hi All,

I have been using this excellent forum to help me set up an assessment spreadsheet (attached)

The idea is that staff enter a fine grade e.g. C1,C2,C3,D1,D2,D3 etc and then for each aspect an average is worked out.

I have managed to undertake this when all cells are filled in however when a cell does not have a grade this average does not seem to work as it counts blank cells for an average so if there are only 2 grades as in row 4 entered a result is not returned.

So is there a way to ignore blank cells when carrying out the formulae in column X,Y and AA.

Many thanks

Olly