footerCallback based on two columns?

yepwingtim

I have a table like this

http://live.datatables.net/vezehaha/

How can I do the average FTE calculation based on the month?

Lets say for Loc_No = 4001 Month_No 1,2, and 3
I need month 1 to be 88/120 + 1 = 1.73
month 2 = 1
month 3 = 1

3.73/3 = 1.24 FTE

yepwingtim

Another alternative is get a count of the distinct months but im not sure how to do that

yepwingtim

Thank you!