I have a table with region, leaders (rows), points per leader (value), and
date (column).

I want to get the average number of points per region per day.

If I summarize the data using sum, I get the total number of points, not the
average.
If I summarize the data using average, I get the average number of points
per person per day, not the average numer of points of the region per day.

What need is to divide the total number of points of each region, each day,
by the number of persons that actually get points that day.

Any ideas?