Using Average and ignoring cells with #div/0

Hello,
I've attached an image below but I'm not sure you can see it. Jan - Dec and YTD average are in cells I5 to I17 and their corresponding values are in cells J5 to J17.

I need to average the column of twelve monthly percentage scores. The problem I'm having is that the cells all pull their own values from other cells on the same sheet. The values are averages of each month, Jan, Feb, etc. Those other cells are currently blank. For example, lets say this is March 2015. I have scores for January, February, and March but April to December are all empty so the values in those cells are all #div/0. How do I calculate a year to date average for the year while ignoring the cells with #div/0?

Thanks for your help

I've solved my own thread!

In cell J5 (and J6 through J16, slightly differently) I have formula

=IF(SUM(B4:B23)=0,0,AVERAGE(B4:B23))

This returns zero if B4:B23 is blank or zero and it gives me the average for that area otherwise.

In cell J17 I have formula

=AVERAGE(B4:B23,D4:D23,F4:F23,B25:B44,D25:D44,F25:F44,B46:B65,D46:D65,F46:F65,B67:B86,D67:D86,F67:F86)

This gives me the average of all of the scores in the above fields.