Fill-down for the AVERAGE function, problem

Hi!

This is my first post, here goes...

I am trying to create a table showing the yearly average occupancy rates per quarter for every year between may 1998 and december 2008 inclusive (for licensed hotels, motels and guest houses, and serviced apartments in Australia; if that interests you).

I have a spreadsheet with a row of data showing the appropriate quarterly results for those dates. Let's say the data for this is displayed A1 through to A44.

For the yearly per quarter averages, let's say they are to go from B1 through to B11, I know I could put, for each year, an average formula with the relevant data range. Finding this to be tedious, I tried to fill-down.

I learnt the hard way however (not being too aware of how excel's grammar ticks) that the fill down function will not work for me. i.e., if B1 contained the average for the data range A1:A4 (the four quarters of 1998), the filled-in B2 would have the data range A2:A5 (i.e. the 2nd quarter of 1998 through to the 3rd quarter of 1999).

The actual question I am working on bores me, but finding a way around this is pretty interesting. I've been looking about and asking friends (you know, those self-titled 'computer-savvy'-type friends...pfft) for hours now. I could've easily done the work cell-by-cell I guess. I could've really slogged it out and finished it by now...

But that's of minimal consequence.

I'm sure there's an answer and it's just pains me to let it slip by. Maybe it's so simple that there are those who would read this and just chortle to themselves, shaking their heads and rolling their eyes. Clucking their tongues even. I don't know what people do in these situations.

Anyway, in short, how would it be possible to make a formula that can be filled-down with the data range beginning after the previous one ended, and so forth?

Please, sorry and thank you so very much... just for reading, even.

Cheers.

If I've understood and you're saying

B1: =Average(A1:A4)
B2: =Average(A5:A8) etc

Then to do this programatically (ie adjust the range as the formula is copied down row by row)

B1: =AVERAGE(INDEX($A$1:$A$44,1+(4*(ROWS(B$1:B1)-1))):INDEX($A$1:$A$44,4*(ROWS(B$1:B1))))
copied down to B11

Using OFFSET approach which is Volatile (ie generally best avoided if using lots and lots of them...):

B1: =AVERAGE(OFFSET($A$1,4*(ROWS(B$1:B1)-1),,4,1))
copied down to B11