Excel 2007 : Recognising increases and decreases with a zero figure

[rachelar]

Hi all, I'm hoping someone can help me.

I have a spreadsheet to record outcomes of a monthly review. There is one worksheet every month with the same table on it, and an analysis sheet at the end.

On the monthly sheets, I will fill in a range of numbers where appropriate, and then calculate an average. This is the formula I am using to calculate the average:

=IF(N4=0,"0",AVERAGE(C4:M4))

I am using this because there may be times when there are no numbers to fill in and N4 counts this. If there are no numbers, I want to avoid the DIV! error that would result from simply using an average formula. So far so good.

The problem comes with the analysis sheet at the end. I have set up a table that monitors whether the average figure changes from month to month. Here is the formula I'm using (modified for each month):

=IF(February!O4>January!O4,"Increase","Decrease")

This is where the problem lies. This formula won't recognise that anything above zero is an increase, and that zero is usually a decrease. As a result, my spreadsheet tells me that zero is an increase on 13.

The other problem is that this is too simplistic, since there will, very rarely, be months where the average remains the same. Ideally, this is what I would like a formula to do:
Increase- "Increase"
Decrease- "Decrease"
The same- "Nil change"

However, this problem isn't so pressing as I think it will happen rarely. I'm more interested in getting the increase/decrease formula to recognise zero. Can anyone help?

Thanks in advance!