Table Summaries by column

I would like to control what kind of summary a table does column by column. For example some columns I'd like a sum and some I'd like an average.

Right now the best I can do is have the whole table do a sum and average, and turn some columns to calculate both or neither. But that means some columns I want to calculate an average also gives me a sum total result which is just unnecessary and confusing data (for example, averaging percentages, I don't care to see a sum that is 5000% or whatever)

Maybe the best UI would be for the table options to just say "Totals On" or "Totals Off" and then each column you can choose to set a total to avg/sum/etc.

We would find the feature very helpful