AVERAGEIFS with multiple worksheets

[a4turbo]

First I apologize if this has been posted before. I have searched the forum and google for many hours before resorting to post on this forum. If it has been posted before please point me in the right direction.

I am trying to do an "AVERAGEIFS" (not sure if that is what I should even be doing) involving multiple worksheets.

I currently have a working solution for a single worksheet:

=AVERAGEIFS(E5:E200,E5:E200,">0",N5:N200,"=Sale")

But now I need that same formula to take the average of multiple worksheets. Every worksheet has the same data in the same location.

The reason for this is so that I can put this formula on every worksheet and not have to flip back and forth to compare my total average vs. the current year I am on. I don't know if it matters or not but my worksheets are labeled by year (i.e. 2009, 2010, 2011).

Thanks.