Array of worksheets

I have been using Excel to provide monthly cashflow analysis for a holiday property business. It shows income and expenditure under various categories with monthly and year-to-date totals. The workbook comprises 12 worksheets, one for each month. Until now everything has been analysed across the whole business.
I now need to provide separate analyses for each of the four properties, plus the common expenses and a monthly summary of all five sheets. This must be a common requirement and I am wondering how best to arrange it. I could simply add another 5 worksheets for every month with helpful tab names but suspect there is a more elegant method of arranging them as 6 x 12 worksheets.
Any suggestions would be very welcome.
Nick

Since I have had no replies so far let me restate the problem more briefly and (I hope) more clearly:-

I am using Excel to provide a monthly income and expenditure analysis under various headings (columns) with current month and year-to-date totals. The workbook contains 12 worksheets, one for each month. I now need to break down each monthly analysis to show the constituent parts of the business plus a monthly summary for the whole with month and year-to-date totals, as before.

I am seeking the most elegant and efficient arrangement but can so far think of only two ways of representing this, neither of which seem ideal.
First, I could simply have a workbook with extra worksheets: AprilTotals, AprilDept1, AprilDept2,..., MayTotals, MayDept1, MayDept2, ... This may be the simplest solution.
Second, I could have 12 workbooks; but is it possible to accumulate totals across separate workbooks?
Is there a third alternative with one, integrated workbook containing 12 worksheets, each of which contains a number of sub-worksheets? Or is there another way altogether of looking at this? It must be a common requirement. I would like to build this the right way before entering all the data.
I'd be grateful for any comments.

Thanks shg.
I haven't used pivot tables before. Now I know what I'm looking for I can see that they are probably the answer. I will learn how to use them and expect it will be fairly straight forward to set up what I need.
Problem solved (I think)!