Excel 2007 : Rearranging data set

So basically: I'm creating a data set by adding certain cells together from another set to make new variables. The original columns are year (from 1990 to 2010), month, lbs of a certain type of fish landed (for each month), and region (as in Chesapeake Bay, Gulf of Mexico, etc.)

I need to create a data set where I have a column for lbs of fish landed summed across all regions, for each month in that 21 year period. I've sorted by year and month so it's easy to just add, say, the numbers for all of the regions in Jan 1990 together, then Feb 1990, and so on. There's also some missing numbers for certain regions, for instance the Gulf region is missing certain years. I'm looking for a way to speed up what I'm doing instead of having to manually do a SUM function for each cell (12 months times 21 years = 252 rows, and that's just for the first type of fish).

Sorry if this is hard to understand, I'm writing this quickly just before I leave work to let it sit overnight.

Please ask questions to clarify anything that you don't understand (if it would help anyone understand what I'm looking for I suppose I could attach the original file, but I won't do this yet because the information may not be supposed to be sitting out on the internet), and thanks a bunch in advance. At this point I know I could do it, but it would just take quite a long time because I'm going to have to do this for a fairly large number of different types of fish.

Thanks again.

EDIT: Ok, I uploaded the excel file so you can look at it. Let me know if you need any more clarification.

You could try using a pivot table, but apart from that suggestion, i think you'll need to provide a sample workbook if we are to help you out. You should strip/scramble/randomize sensitive data before uploading.

As for tiltle, you could change it to, e.g., "Rearranging data set".

Hello mbranner, and welcome to the forum. Thanks for amending your title.

Do you want a summed table on each sheet, or one table on a sheet where they are all summed?

It's a good case for a pivot table. Have a look at the attached:

I didn't see your latest reply before posting above example. But you could just append all your tables underneath eachother, and then use a pivottable on that new appended table.

Thanks Søren. A couple follow-ups, though.

1. Whenever I try to click anywhere in that document, this message pops up: "PivotTable field name already exists." I changed the titles at the top of the table but now I can't edit anything.

2. Less important, but the months are out of order in the table. I could probably figure this out if I could actually change the spreadsheet now, so don't worry about this so much.

I'm going to try and make my own pivot table now, but this seems like a strange error to pop up.

EDIT: This is weird. I can't close the spreadsheet you attached, and even though I can minimize it whenever I try to select a cell on another spreadsheet, yours pops up along with that same error message.

Try from scratch again: delete all pivot tables, close everything and open you original workbook again. I'm not sure why you get that error, but what I was thinking you could do is:
1) Append all your tables underneath eachother. Only headers in the first row!
2) It doesn't matter how your data is sorted.
3) Select all data at once including headers.
4) Insert pivot table.

If you are still running in to problems, then try to upload a workbook where you've appended all the individual tables into one.