#div/0!

I would like the error #DIV/0! not be visable for the following formula:
=AVERAGE('Name 1'!C7,'Name 2'!C7,'Name 3'!C7,'Name 4'!C7,'Name 5'!C7,'Name 6'!C7,'Name 7'!C7,'Name 8'!C7,'Name 9'!C7,'Name 10'!C7,'Name 11'!C7,'Name 12'!C7,'Name 13'!C7,'Name 14'!C7,'Name 15'!C7)
any and all help would be apperciated
Thank you in Advance

You could probably reduce that to

=AVERAGE('Name 1:Name 15'!C7)

and then to show a blank instead of error when there are no numbers..

=IF(COUNT('Name 1:Name 15'!C7),AVERAGE('Name 1:Name 15'!C7),"")