Hello!

I made a spreadsheet where data can be entered into 8 columns.  In eac
column for each day, this data has a formula run on i
(=(E16-E$15)/E$15, for example).  Then sum of these calculations ar
taken and averaged (=SUM(C17:J17)/8).  The problem is, towards th
bottom of this spreadsheet there won't be 8 columns of data anymore
but I still want a valid average generated.   Maybe after a week o
two, there is only 7 columns of data, and after three weeks only
columns of data available.  The amount of rows into the spreadshee
that this lack of data happens is constantly different.  I have th
framework for the entire spreadsheet created as a template so that onl
the data needs to be entered.  

Is there a command which will dynamically average whatever data i
available?  (=SUM(C17:J17)/8) doesn't cut it  :(

TIA!