How to show the percentage of the selected value over all values?
Suppose I have two columns (NAME and POINTS) like this:
with each name potentially appearing more than once.
I have built a small box to display the sum of points (merely SUM(POINTS)) and, when I select John in the above example, the box shows 9 (since 4 + 5 = 9).
Now, I wish to build another box, to display the percentage which this points represents over all the set of names. In the above example, since the column POINTS sums 40, if no one is selected, I want the box shows 100% (= 40/40) and, if I select John, I want the box shows 22,5% (= 9/40). Is it possible?